: OCR past-paper questions pack
Back to the topic page

Amount of substance (moles)

Past-paper questions pack

Name
Class
Date set
Date due
Score/ 835

Questions are numbered; the mark schemes (the answer key) follow on separate pages so the question pages can be handed out alone. www.chemistryaleveltutor.com

OCR AS and A-level Chemistry past-paper questions since 2016 · 291 parts · mark schemes follow the questions · www.chemistryaleveltutor.com · Questions and mark schemes © OCR

1. June 2025 · Paper 1 · Q2 · 1 marks ·
2 11.895 g of hydrated cobalt(II) chloride, CoCl 2•xH2O, is heated to remove the water of crystallisation. After heating to constant mass, the mass of the anhydrous salt was 6.495 g. What is the value of x? A 3 B 5 C 6 D 7 Your answer [1]
2. June 2025 · AS Paper 1 · Q3 · 1 marks ·
3 What is the number of hydrogen atoms in 6.8 g NH3? A 2.408 × 1023 B 3.612 × 1023 C 7.224 × 1023 D 1.806 × 1024 Your answer [1]
3. June 2025 · AS Paper 1 · Q4 · 1 marks ·
4 Which reaction to extract iron (Fe) has the highest atom economy? A 2Al + Fe2O3 2Fe + Al 2O3 B FeO + CO Fe + CO2 C Fe2O3 + 3CO 2Fe + 3CO2 D 2Fe2O3 + 3C 4Fe + 3CO2 Your answer [1]
4. June 2025 · Paper 1 · Q4 · 1 marks ·
4 What volume, in cm3, of 0.250 mol dm–3 barium hydroxide solution is required to exactly neutralise 25.0 cm3 of 0.115 mol dm–3 hydrochloric acid? Ba(OH)2(aq) + 2HCl (aq) BaCl 2(aq) + 2H2O(l) A 5.75 B 11.50 C 23.00 D 54.35 Your answer [1]
5. June 2025 · Paper 1 · Q19(c) · 6 marks ·
(c)* A student plans to prepare a buffer solution with a pH of 4.85 using propanoic acid, CH3CH2COOH, and sodium propanoate, CH3CH2COONa. Ka for CH3CH2COOH = 1.32 × 10–5 mol dm–3. The student mixes 125 cm3 of 0.180 mol dm–3 CH3CH2COOH(aq) with a calculated mass of CH3CH2COONa(s). The student assumes that the volume of the solution does not change. • Calculate the mass of CH3CH2COONa needed to make 125 cm3 of a buffer solution with a pH of 4.85. • Explain why this solution resists changes in pH when a small amount of alkali is added. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [6] Additional answer space if required. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
6. June 2025 · Paper 1 · Q21(b)(ii) · 4 marks ·
(ii) An iron(II) complex contains two different ligands: C5H5N, and Cl –. The complex has a molar mass of 442.8 g mol–1 and the following percentage composition by mass: Fe, 12.6%; C, 54.3%; H, 4.5%; N, 12.6%; Cl , 16.0% Determine the empirical formula of the iron(II) complex. Deduce the number of C5H5N ligands in the complex and the coordination number of the iron(II) ion. Empirical formula of iron(II) complex ................................................................ Number of C5H5N ligands ............................................................... Coordination number of iron(II) ion ................................................................ [4]
7. June 2025 · AS Paper 1 · Q21(d)(i) · 3 marks ·
(d) Magnesium reacts with dilute hydrochloric acid, as shown in the equation. Mg(s) + 2HCl (aq) MgCl 2(aq) + H2(g) A student reacts an excess of Mg with 24.5 cm3 HCl (aq) using the apparatus below. 100 cm3 gas syringe Dilute hydrochloric acid Magnesium The student measures the volume of gas collected over time. All gas volumes are measured at RTP. A graph of the student’s results is shown in Fig. 21.1 below. Fig. 21.1 70.0 60.0 50.0 Volume 40.0 of gas collected / cm3 30.0 20.0 10.0 0.0 0 5 10 15 20 25 30 35 40 Time / s (i) Calculate the concentration of HCl that the student used. Give your answer to 2 significant figures and in standard form. Concentration of HCl = ......................................... mol dm–3 [3]
8. June 2025 · Paper 1 · Q21(d)(i) · 5 marks ·
(d) Mixture A is a mixture of copper(II) sulfate crystals, CuSO4•5H2O and iron(II) sulfate crystals, FeSO4•7H2O. A student carries out a titration to determine the percentage by mass of CuSO4•5H2O in Mixture A. The student uses the following method. Step 1 Dissolve 9.51 g of Mixture A in water and make up the solution to 250.0 cm3 in a volumetric flask. Step 2 Pipette 25.0 cm3 of the solution from Step 1 into a conical flask and add an excess of aqueous potassium iodide, KI(aq). The copper(II) ions react with iodide ions to form a precipitate of copper(I) iodide and a solution of iodine. 2Cu2+(aq) + 4I–(aq) 2CuI(s) + I2(aq) Step 3 Titrate the contents of the conical flask from Step 2 with 0.0800 mol dm–3 sodium thiosulfate, Na2S2O3, using starch as the indicator. I2(aq) + 2S2O3 2–(aq) 2I–(aq) + S4O6 2–(aq) Step 4 Repeat Step 2 and Step 3 to obtain concordant titres and calculate the mean titre. Results Mean titre = 31.15 cm3 (i) Calculate the percentage by mass of CuSO4•5H2O in Mixture A. Give your answer to 3 significant figures. Percentage of CuSO4•5H2O in Mixture A = ....................................................... % [5]
9. June 2025 · AS Paper 1 · Q25(c) · 5 marks ·
(c) 25.9 g of alcohol F is completely combusted in oxygen at a temperature of 100 °C and 1.50 × 105 Pa pressure. The equation for this reaction is: C4H10O + 6O2 4CO2 + 5H2O Calculate the volume of CO2(g) produced, in cm3. Give your answer to an appropriate number of significant figures. Volume of CO2(g) = ................................................. cm3 [5]
10. June 2025 · AS Paper 2 · Q1(c)(i) · 4 marks ·
(c) The student mixes 40.0 cm3 of 1.40 mol dm–3 HCl and 40.0 cm3 of 1.40 mol dm–3 NaOH. The temperature rises by 9.40 °C (i) Calculate the enthalpy change of neutralisation, in kJ mol–1. Give your answer to 3 significant figures. Assume that the density of all solutions and the specific heat capacity, c, of the reaction mixture is the same as for water. Enthalpy change of neutralisation = ........................................... kJ mol–1 [4]
11. June 2025 · Paper 2 · Q2 · 1 marks ·
2 0.0200 mol of the compound below reacts with Br2(aq) to make a saturated compound. How many grams of Br2 are needed for this reaction? Cl A 3.20 B 6.39 C 7.99 D 12.80 Your answer [1]
12. June 2025 · AS Paper 2 · Q2(b)(i) · 2 marks ·
(b) A student adds 1.51 g of barium carbonate, BaCO3 (molar mass 197.3 g mol–1), to an excess of dilute nitric acid. The equation is shown below. BaCO3(s) + 2HNO3(aq) Ba(NO3)2(aq) + H2O(l) + CO2(g) The student uses the following apparatus. 250 cm3 measuring cylinder Stopper Barium carbonate and dilute nitric acid Water (i) Calculate the volume, in cm3, of gas the student expects to be produced at room temperature and pressure (RTP). Give your answer to 3 significant figures. Volume of gas .................................................. cm3 [2]
13. June 2025 · AS Paper 2 · Q2(b)(ii) · 2 marks ·
(ii) The volume of gas collected is less than the calculated volume. Suggest two reasons for this difference. 1 ....................................................................................................................................................... .......................................................................................................................................................... 2 ....................................................................................................................................................... .......................................................................................................................................................... [2]
14. June 2025 · AS Paper 2 · Q2(b)(iii) · 1 marks ·
(iii) Suggest one way in which the student could modify the apparatus to produce a volume closer to the calculated volume. .......................................................................................................................................................... ..................................................................................................................................................... [1]
15. June 2025 · Paper 2 · Q3 · 1 marks ·
3 The skeletal structure of a medicinal drug is shown below. How many hydrogen atoms are in its molecular formula? H N Cl Cl A 14 B 15 C 17 D 19 Your answer [1]
16. June 2025 · AS Paper 2 · Q3(a)(iii) · 5 marks ·
(iii) Calculate the mass, in mg, of malic acid in one tablet. Assume that malic acid (molar mass 134.0 g mol–1) is the only acid in the tablets. Give your answer to 3 significant figures. Mass of malic acid ................................................... mg [5]
17. June 2025 · AS Paper 2 · Q4(b)(ii) · 2 marks ·
(ii) Use the information in Table 4.1 to calculate the mass of carbon dioxide formed when 1.00 kJ of energy is released during the complete combustion of pentane. Mass of carbon dioxide .......................................................g [2]
18. June 2025 · Paper 2 · Q5 · 1 marks ·
5 0.200 mol of HOOCCH2CH2COOH is reacted with 0.300 mol NaOH. How many water molecules are formed? A 1.204 × 1023 B 1.806 × 1023 C 2.408 × 1023 D 3.612 × 1023 Your answer [1]
19. June 2025 · AS Paper 2 · Q5(c) · 6 marks ·
(c)* 2-Chlorobutane, CH3CH2CHCl CH3, is an organic liquid with a boiling point of 70 °C. A student prepares 2-chlorobutane from butan-2-ol, CH3CH2CHOHCH3, as shown in the equation below. CH3CH2CHOHCH3 + NaCl + H2SO4 CH3CH2CHCl CH3 + NaHSO4 + H2O The student’s method is outlined below. • Add 9.25 g CH3CH2CHOHCH3 to an excess of NaCl (aq) in a pear-shaped flask. • Add an excess of concentrated sulfuric acid. • Heat the flask under reflux for about 45 minutes. The student obtains a reaction mixture containing an organic layer (density = 0.87 g cm–3) and an aqueous layer (density = 1.00 g cm–3). After purification, the percentage yield of CH3CH2CHCl CH3 is 65.0 %. Describe how the student could obtain a pure, dry sample of CH3CH2CHCl CH3 from the reaction mixture and explain the reason for carrying out each purification step. Calculate the mass of pure CH3CH2CHCl CH3 that would be expected from this preparation. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [6] Extra answer space if required. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
20. June 2025 · Paper 2 · Q6 · 1 marks ·
6 Propene can be prepared using the reactions shown. Which reaction has the lowest atom economy? A C3H7Br C3H6 + HBr B C12H26 2C3H6 + C6H14 C C8H18 C3H6 + C5H12 D C3H7OH C3H6 + H2O Your answer [1]
21. June 2025 · Paper 2 · Q16(b) · 3 marks ·
(b) The table below shows incomplete information about two hydrocarbons. Complete the table. Skeletal formula Molecular formula Number of σ bonds Number of π bonds [3]
22. June 2025 · Paper 2 · Q17 · 6 marks ·
17* This question is about an organic synthesis. A student plans a two-stage synthesis of compound F from compound D, as shown below. Cl OH OH O Stage 1 Stage 2 Compound E Compound D Compound F Plan a two-stage synthesis for the preparation of 2.50 g of compound F from compound D. The overall percentage yield of compound F from compound D is 31.5%. In your answer include the mass of compound D required, reagents and equations for each step. [6] .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Extra answer space if required. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
23. June 2025 · Paper 3 · Q2(a)(ii) · 3 marks ·
(ii) What is the number of H atoms in 8.45 g of 2,3‑dimethylhexan‑1‑ol? Give your answer to 3 significant figures and in standard form. Number of H atoms = ......................................................... [3]
24. June 2025 · Paper 3 · Q2(b)(ii) · 4 marks ·
(ii) The student uses the reaction of nuromol tablets with Na2CO3(aq) to determine the mass of ibuprofen and the mass of paracetomol in one nuromol tablet. The student’s method is outlined below. • Weigh four nuromol tablets. • Add the tablets to an excess of aqueous sodium carbonate. • Collect the gas produced and measure its volume. Results Mass of four nuromol tablets = 2.80 g Volume of gas collected at RTP = 48.0 cm3 Assume that ibuprofen is the only compound in nuromol tablets that reacts with Na2CO3(aq). Determine the mass of ibuprofen and the mass of paracetomol, in mg, in one nuromol tablet. Mass of ibuprofen = ......................................................... mg Mass of paracetamol = ......................................................... mg [4]
25. June 2025 · Paper 3 · Q2(c) · 5 marks ·
(c) Barium hydroxide, Ba(OH)2, is an alkali. A student is supplied with a solution of Ba(OH)2 with a concentration of 46.80 g dm–3 at 25 °C. The student dilutes 20.0 cm3 of this solution of Ba(OH)2 with water and the solution is made up to 100.0 cm3 at 25 °C. Calculate the pH of the diluted solution of Ba(OH)2 at 25 °C. Give your answer to 2 decimal places. pH = .......................................................... [5]
26. June 2025 · Paper 3 · Q4(b)(i) · 1 marks ·
(b) The structure of a neutral nickel(II) complex, A, is shown below. O O OH2 O O Ni N N H2 H2 OH2 Complex A (i) What is the empirical formula of complex A? ..................................................................................................................................................... [1]
27. June 2025 · Paper 3 · Q5(a)(ii) · 4 marks ·
(ii) Calculate the mass of LiAl H4 that the student should use in Step 2 and the percentage yield of pure C6H5CH2OH obtained in Step 4. Give the mass of LiAl H4 and the percentage yield of pure C6H5CH2OH to 3 significant figures. Mass of LiAl H4 = ............................................................ g Percentage yield of pure C6H5CH2OH = ............................................................% [4]
28. June 2025 · Paper 3 · Q6 · 6 marks ·
6* The enthalpy change of Reaction 6.1, ∆H1, shown below, is difficult to measure directly by experiment. 2NaHCO3(s) Na2CO3(s) + H2O(l) + CO2(g) ∆H1 Reaction 6.1 The enthalpy changes of reaction for the reactions of Na2CO3 and NaHCO3 with excess HNO3(aq) can be measured by experiment. The reactions are shown below as Reaction 6.2 and Reaction 6.3. Na2CO3(s) + 2HNO3(aq) 2NaNO3(aq) + H2O(l) + CO2(g) ∆H2 Reaction 6.2 NaHCO3(s) + HNO3(aq) NaNO3(aq) + H2O(l) + CO2(g) ∆H3 Reaction 6.3 A student reacts Na2CO3(s) with HNO3(aq) to find ∆H2 for Reaction 6.2. Student’s method Weigh a bottle containing Na2CO3(s) and weigh a polystyrene cup. Add about 30 cm3 of 1.00 mol dm–3 HNO3(aq) to the polystyrene cup and measure its temperature. Add the Na2CO3(s), stir the mixture, and measure the maximum temperature reached. Weigh the empty bottle and weigh the polystyrene cup with the final solution. Mass readings Mass of bottle + Na2CO3(s) / g 3.26 Mass of empty bottle / g 1.29 Mass of polystyrene cup / g 21.08 Mass of polystyrene cup + final solution / g 54.58 Temperature readings Initial temperature of HNO3(aq) / °C 20.0 Maximum temperature of final solution / °C 24.0 The student follows a similar method and reacts NaHCO3(s) with HNO3(aq) to find ∆H3 for Reaction 6.3. The student calculates ∆H3 for Reaction 6.3 as +19.8 kJ mol–1. Calculate ∆H2 for Reaction 6.2 and determine the enthalpy change of Reaction 6.1, ∆H1. Assume that the density and specific heat capacity, c, of the final solution are the same as for water. Show your working, including an energy cycle linking the enthalpy changes. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [6] Extra answer space if required. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
29. June 2024 · AS Paper 1 · Q3 · 1 marks ·
3 A nitrogen oxide contains 36.84% of nitrogen by mass. What is the empirical formula of the nitrogen oxide? A NO B NO2 C N2O D N2O3 Your answer [1]
30. June 2024 · Paper 1 · Q3 · 1 marks ·
3 Which chemical process is the most sustainable in terms of the atom economy of the iron produced? A Fe2O3 + 3CO 2Fe + 3CO2 B Fe2O3 + 3H2 2Fe + 3H2O C 2Fe2O3 4Fe + 3O2 D 2Fe2O3 + 3C 4Fe + 3CO2 Your answer [1]
31. June 2024 · AS Paper 1 · Q4 · 1 marks ·
4 Carbon monoxide reacts with oxygen to form carbon dioxide: 2CO(g) + O2(g) 2CO2(g) Which volumes of CO(g) and O2(g) produce the largest volume of CO2(g)? All gas volumes are measured at RTP. A 1.00 dm3 CO and 4.00 dm3 O2 B 2.00 dm3 CO and 3.00 dm3 O2 C 3.00 dm3 CO and 2.00 dm3 O2 D 4.00 dm3 CO and 1.00 dm3 O2 Your answer [1]
32. June 2024 · Paper 1 · Q7 · 1 marks ·
7 The equation for the reaction of sulfuric acid with potassium hydroxide is shown below. H2SO4(aq) + 2KOH(aq) K2SO4(aq) + 2H2O(l) 25 cm3 of 1.00 mol dm–3 H2SO4 is reacted with excess KOH. The energy given out is 2.8 kJ. What is the enthalpy change of neutralisation, in kJ mol–1? A –56 B –70 C –112 D –224 Your answer [1]
33. June 2024 · AS Paper 1 · Q8 · 1 marks ·
8 In the UK, water companies typically treat drinking water with chlorine gas at a concentration of 0.500 mg dm–3 or less. Which statement about UK drinking water is correct? A Chlorine in drinking water can catalyse the breakdown of ozone. B Chlorine may form toxic chlorinated hydrocarbons. C Drinking water with a chlorine gas concentration of 0.500 mg dm–3 contains 2.12 × 1018 chlorine molecules in each dm3. D In hot weather, chlorine can vaporise from drinking water to cause global warming. Your answer [1]
34. June 2024 · Paper 1 · Q19(b)(i) · 5 marks ·
(b) A student titrates a 10.0 cm3 sample of ethanoic acid, CH3COOH, against an aqueous solution of 0.0560 mol dm–3 Ba(OH)2. 2CH3COOH + Ba(OH)2 Ba(CH3COO)2 + 2H2O The student used a pH meter to measure the pH of the mixture after every addition of Ba(OH)2 throughout the titration. The student’s results are shown below. 12 11 10 9 8 7 pH 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 volume of Ba(OH)2 / cm3 (i) Draw a best-fit curve on the graph and calculate the concentration of the CH3COOH solution. CH3COOH concentration = .......................................... mol dm–3 [5]
35. June 2024 · Paper 1 · Q21(b) · 4 marks ·
(b) Potassium iodate tablets prevent the uptake of radioactive iodine in the human body following a nuclear accident. The mass of potassium iodate(V), KIO3, in a tablet can be determined by reaction with an aqueous solution of potassium iodide, KI, in the presence of acid. IO3 – + 5I– + 6H+ 3I2 + 3H2O A chemist finds that two KIO3 tablets react with exactly 26.2 cm3 0.150 mol dm–3 KI. Calculate the mass, in mg, of KIO3 in one tablet. Give your answer to the nearest whole number. mass KIO3 = ................................................... mg [4]
36. June 2024 · AS Paper 1 · Q21(c) · 3 marks ·
(c) The iron compound, Fe(NO3)3, decomposes when heated. The equation for the decomposition of Fe(NO3)3 is shown below. 4Fe(NO3)3(s) 2Fe2O3(s) + 12NO2(g) + 3O2(g) Molar mass of Fe(NO3)3 = 241.8 g mol–1 4.836 g of Fe(NO3)3 is heated until it has completely decomposed. Calculate the total volume of gas, in dm3, produced at RTP. total volume of gas = .................................................. dm3 [3]
37. June 2024 · AS Paper 1 · Q22(b)(iii) · 5 marks ·
(iii) Calculate the percentage composition by mass of CH3COOH in the descaler. Assume that CH3COOH is the only acid in the descaler. Give your answer to 3 significant figures. percentage composition by mass = ..................................................... % [5]
38. June 2024 · AS Paper 2 · Q1(d) · 3 marks ·
(d) A student heats 11.50 g of hydrated zinc sulfate, ZnSO4•7H2O, to remove all the water of crystallisation. Calculate the mass of anhydrous zinc sulfate that should be obtained. mass = ....................................................... g [3]
39. June 2024 · AS Paper 2 · Q2(b)(ii) · 3 marks ·
(ii) A student plans to add 0.0100 mol of Ca to 120 cm3 of 0.100 mol dm–3 HCl (aq). When the student carries out this reaction, they are surprised that all the calcium reacts, despite being in excess of the HCl (aq). • Show by calculation that calcium is in excess of the HCl (aq). • Suggest a reason for this unexpected result. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [3]
40. June 2024 · AS Paper 2 · Q3(b) · 6 marks ·
(b)* A student carries out an experiment to determine the enthalpy change for the reaction between zinc and copper(II) nitrate solution. Zn(s) + Cu(NO3)2(aq) Zn(NO3)2(aq) + Cu(s) ΔrH Equation 3.1 The student follows the method outlined below. • Add 100 cm3 of 0.500 mol dm–3 Cu(NO3)2(aq) to a beaker. • Measure the temperature of the solution. • Add excess zinc to the beaker. • Stir the mixture and record the maximum temperature. The temperature of the solution changes from 19.5 °C to 38.1 °C. Calculate ΔrH, in kJ mol–1, for equation 3.1. State any assumptions you have made in your calculation. Suggest improvements for obtaining a more accurate value for ΔrH. [6] .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Extra answer space if required .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
41. June 2024 · AS Paper 2 · Q4(b)(iii) · 3 marks ·
(iii) The student uses 50.0 cm3 of H2O2 in the experiment. Equation 4.1 shows the reaction that takes place. 2H2O2(aq) 2H2O(l) + O2(g) Equation 4.1 Calculate the concentration of H2O2, in mol dm–3, required to produce 90 cm3 of O2(g) at RTP. concentration = .......................................... mol dm–3 [3]
42. June 2024 · Paper 2 · Q6 · 1 marks ·
6 4.30 g of the alcohol C5H9OH, (Mr = 86.0), is burned in oxygen. C5H9OH(l) + 7O2(g) 5CO2(g) + 5H2O(l) Which volume of oxygen gas is needed, in dm3, for this complete combustion of C5H9OH, at RTP? A 1.2 B 2.4 C 5.8 D 8.4 Your answer [1]
43. June 2024 · Paper 2 · Q10 · 1 marks ·
10 1.35 g of ethylamine gas, CH3CH2NH2 (Mr = 45.0), is reacted with 20 cm3 of 2.0 mol dm–3 hydrochloric acid forming a solution of ethylammonium chloride. CH3CH2NH2(g) + HCl (aq) CH3CH2NH3 +(aq) + Cl –(aq) What is the concentration of ethylammonium chloride in mol dm–3? A 0.03 B 0.67 C 1.50 D 2.00 Your answer [1]
44. June 2024 · Paper 2 · Q23(c) · 3 marks ·
(c) Calculate the percentage yield of compound H. Give your answer to three significant figures. percentage yield = ............... % [3]
45. June 2024 · Paper 3 · Q1(b) · 1 marks ·
(b) Water is added to 10.0 cm3 of 0.750 mol dm–3 HCl (aq) to produce 100 cm3 of diluted HCl (aq). What is the pH of the diluted HCl (aq)? Give your answer to 2 decimal places. pH = ................... [1]
46. June 2024 · Paper 3 · Q1(d) · 5 marks ·
(d) A student is provided with hydrated copper(II) nitrate, Cu(NO3)2•3H2O. The student needs to prepare a standard solution of Cu(NO3)2•3H2O with a concentration of 0.200 mol dm–3. The student has access to usual laboratory apparatus and equipment. Describe how the student would prepare 100.0 cm3 of this solution, giving quantities, apparatus and method. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [5]
47. June 2024 · Paper 3 · Q2(a)(iii) · 2 marks ·
(iii) Hydrogen gas is being considered as a household fuel to replace methane. The enthalpy change of formation, ΔfH, for H2O(l) is –285.8 kJ mol–1. Determine the energy released when 60.0 m3 of hydrogen is used as a household fuel at RTP. Give your answer to 3 significant figures and in standard form. energy released = .................................................... kJ [2]
48. June 2024 · Paper 3 · Q2(b)(ii) · 3 marks ·
(ii) Determine the formula of compound A. formula of A = .......................................................... [3]
49. June 2024 · Paper 3 · Q2(c)(i) · 1 marks ·
(c) Compound B, shown below, is an antiviral medicine. HO OH O O N O HO N N O H compound B (i) What is the molecular formula of compound B? ..................................................................................................................................................... [1]
50. June 2024 · Paper 3 · Q3(b)(iv) · 6 marks ·
(iv)* In the titration, 5 mol of iron(II) ethanedioate reacts with 3 mol of manganate(VII) ions. Analyse the student’s results to find the number of waters of crystallisation, x, in the hydrated iron(II) ethanedioate, FeC2O4•xH2O. [6] .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Extra answer space if required. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
51. June 2023 · Paper 1 · Q1 · 1 marks · AO1
1 Which sample contains the greatest number of molecules? A 35.0 g of C2H2 B 45.0 g of C2H6 C 60.0 g of C4H10 D 100.0 g of C6H6 Your answer [1]
52. June 2023 · AS Paper 1 · Q2 · 1 marks · AO1
2 A hydrocarbon contains 85.71% carbon by mass. What is the empirical formula of the hydrocarbon? A CH B CH2 C CH4 D C2H4 Your answer [1]
53. June 2023 · Paper 1 · Q2 · 1 marks · AO2
2 0.688 g of an oxide of manganese is reduced by hydrogen gas to form manganese metal and 0.235 g of water. What is the formula of the oxide of manganese? A MnO B MnO2 C Mn2O3 D Mn3O4 Your answer [1]
54. June 2023 · AS Paper 1 · Q3 · 1 marks · AO1
3 Hydrogen can be prepared industrially by the reaction of methane with steam. The equation is shown below. CH4(g) + 2H2O(g) 4H2(g) + CO2(g) What is the atom economy of hydrogen for this process? A 3.8% B 4.3% C 15.4% D 17.4% Your answer [1]
55. June 2023 · Paper 1 · Q3 · 1 marks · AO2
3 How many hydrogen atoms are in 2.50 g of pharmacolite, CaHAsO4•2H2O (Mr = 216.0)? A 6.97 × 1021 B 2.09 × 1022 C 2.79 × 1022 D 3.48 × 1022 Your answer [1]
56. June 2023 · Paper 1 · Q4 · 1 marks · AO2
4 40.0 cm3 of 0.200 mol dm–3 HCl is added to 60.0 cm3 of 0.100 mol dm–3 NaOH. What is the concentration of the resulting solution? A 0.0200 mol dm–3 HCl and 0.0200 mol dm–3 NaCl B 0.0200 mol dm–3 HCl and 0.0400 mol dm–3 NaCl C 0.0200 mol dm–3 HCl and 0.0600 mol dm–3 NaCl D 0.0600 mol dm–3 HCl and 0.0200 mol dm–3 NaCl Your answer [1]
57. June 2023 · AS Paper 1 · Q7 · 1 marks · AO2
7 How many oxygen atoms are in 120.2 g of SiO2? A 3.01 × 1023 B 1.20 × 1024 C 2.41 × 1024 D 3.61 × 1024 Your answer [1]
58. June 2023 · AS Paper 1 · Q8 · 1 marks · AO2
8 Magnesium nitrate, Mg(NO3)2, decomposes when heated: Mg(NO3)2(s) MgO(s) + 2NO2(g) + ½O2(g) 0.00250 mol of Mg(NO3)2 is decomposed. What is the volume of gas produced, measured at RTP? A 30 cm3 B 60 cm3 C 120 cm3 D 150 cm3 Your answer [1]
59. June 2023 · AS Paper 1 · Q9 · 1 marks · AO2
9 Zinc reacts with aqueous silver nitrate, as shown in the equation: Zn(s) + 2AgNO3(aq) 2Ag(s) + Zn(NO3)2(aq) 0.10 g of zinc is added to 15 cm3 of 0.25 mol dm–3 aqueous silver nitrate. What is the mass of silver metal that would be formed? A 0.16 g B 0.20 g C 0.33 g D 0.40 g Your answer [1]
60. June 2023 · AS Paper 1 · Q10 · 1 marks · AO2
10 15.00 cm3 of 18.0 mol dm–3 concentrated hydrochloric acid is diluted with water to prepare 250 cm3 of dilute hydrochloric acid. What is the concentration, in mol dm–3, of the dilute hydrochloric acid? A 0.0675 B 0.270 C 0.300 D 1.08 Your answer [1]
61. June 2023 · Paper 1 · Q18(a) · 3 marks · AO2
18 This question is about enthalpy changes of reactions involving hydrocarbons. (a) A student determines the enthalpy change of combustion, ∆cH, of heptane, C7H16, using the method outlined below. • Add 150 g of water to a beaker and measure its temperature. • Weigh a spirit burner containing heptane and use it to heat the water. • Extinguish the flame and record the maximum temperature reached by the water. • Reweigh the spirit burner. The temperature of the water increased by 10.5 °C. The spirit burner decreased in mass by 0.133 g. Use the student’s results to determine the enthalpy change of combustion of heptane, ∆cH (C7H16), in kJ mol–1. ∆cH (C7H16) = ........................................... kJ mol–1 [3]
62. June 2023 · Paper 1 · Q19(b) · 5 marks · AO2, 3
(b) N2O4 reacts fully with oxygen to form a different oxide of nitrogen, oxide A, as the only product. Oxide A is collected and cooled to 75.0 °C at a pressure of 101 kPa. Under these conditions, oxide A is a gas that occupies a volume of 74.0 cm3 and has a mass of 0.280 g. Calculate the molar mass of oxide A and suggest its molecular formula. molar mass = .................................................. g mol–1 molecular formula = ............................................................... [5]
63. June 2023 · Paper 1 · Q20(b) · 5 marks · AO1, 2
(b) A student reacts strontium metal with water to make a 250.0 cm3 solution of aqueous strontium hydroxide, Sr(OH)2. The solution contains 0.145 g of strontium hydroxide. • Write an equation for the reaction of strontium with water. • Calculate the pH of this 250.0 cm3 solution of strontium hydroxide at 40 °C. You should refer back to Table 20.1 at the start of (a). Give your answer to 2 decimal places. Equation ................................................................................................................................... Calculation pH = .......................................................... [5]
64. June 2023 · Paper 1 · Q20(c)(ii) · 2 marks · AO3
(ii) The student then reacts 1.00 g of calcium carbonate, CaCO3, with an excess of dilute nitric acid, HNO3. Explain why the student’s two reactions produce different volumes of gas. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2]
65. June 2023 · Paper 1 · Q20(e)(ii) · 4 marks · AO1, 2
(ii) A buffer solution is prepared by dissolving 3.39 g of potassium hydroxide in 250 cm3 of 0.376 mol dm–3 butanoic acid. This buffer solution has a pH of 5.07 at 25 °C. Calculate the acid dissociation constant, Ka, of butanoic acid at 25 °C. Assume that the volume of the solution remains constant at 250 cm3 when the potassium hydroxide is dissolved. Ka = .......................................... mol dm–3 [4]
66. June 2023 · Paper 1 · Q21(a)(iii) · 3 marks · AO2
(iii) Determine the concentration, in mol dm–3, of iron(II) ions in the river water. concentration = .......................................... mol dm–3 [3]
67. June 2023 · AS Paper 1 · Q22(c)(iv) · 4 marks · AO3
(iv) Calculate the amount, in mol, of MOH in 25.0 cm3 of solution and determine the identity of the Group 1 metal M. metal M = .......................................................... [4]
68. June 2023 · AS Paper 2 · Q1(b)(ii) · 4 marks · AO2
(ii) In Reaction 1.2, the percentage yield of titanium from TiCl4 is 72.0%. Calculate the minimum mass, in kg, of sodium that is needed to produce 1.00 kg of titanium. Give your answer to 3 significant figures. mass of sodium = ..................................................... kg [4]
69. June 2023 · AS Paper 2 · Q2(b)(ii) · 4 marks · AO3
(ii) The student obtains 3.28 g of precipitate. Calculate the percentage by mass of NaCl (s) in the 5.00 g mixture. Give your answer to 3 significant figures. percentage by mass of NaCl (s) = ...................................................... % [4]
70. June 2023 · AS Paper 2 · Q3(a) · 6 marks · AO1, 2
3 This question is about halogens and halogen compounds. (a)* Seawater contains very small quantities of dissolved iodide ions. The concentration of potassium iodide, KI, in seawater is 0.150 g dm–3. Iodine can be extracted by bubbling chlorine gas through seawater. Explain why chlorine is more reactive than iodine and determine the volume, in dm3, of seawater that is needed to manufacture 1.00 tonne of iodine, I2. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
71. June 2023 · Paper 2 · Q5 · 1 marks · AO1
5 Oxymetazoline, shown below, is used as a decongestant in the treatment of colds. HO N HN Oxymetazoline How many H atoms are in one molecule of oxymetazoline? A 23 B 24 C 25 D 26 Your answer [1]
72. June 2023 · Paper 2 · Q8 · 1 marks · AO2
8 For complete combustion, 0.100 mol of an alkane requires 22.8 dm3 of O2, measured at RTP. Which alkane has undergone complete combustion? A pentane B hexane C heptane D octane Your answer [1]
73. June 2023 · Paper 2 · Q16(b)(iii) · 3 marks · AO2, 3
(iii) Organic compound B is formed by the substitution of some of the 14 H atoms in 2-methylpentane by Br atoms. 0.8649 g of compound B is heated until it is vaporised. Under the conditions used: • compound B has a volume of 72.0 cm3 • the molar gas volume is 40.0 dm3 mol–1. Determine a possible molecular formula of compound B. molecular formula = .......................................................... [3]
74. June 2023 · Paper 2 · Q18(b) · 3 marks · AO1, 2
(b) Determine the percentage yield of 1,3-dinitrobenzene. Give your answer to 3 significant figures. percentage yield = .................................................... % [3]
75. June 2023 · Paper 2 · Q20(b)(ii) · 3 marks · AO3
(ii) For the treatment of TB, the maximum daily dosage of PAS that should be prescribed is 300 mg per kg of body mass. A child weighs 20.0 kg. Calculate the number of PAS molecules in the maximum daily dosage of PAS for this child. number of PAS molecules = ............................................................... [3]
76. June 2023 · Paper 2 · Q23 · 6 marks · AO1, 3
23* An unknown organic compound is analysed. The results are shown below. Addition of 2,4-DNP No visible change Elemental analysis by mass C, 66.63%; H, 11.18%; O, 22.19% Mass spectrum Molecular ion peak at m / z = 144.0 IR spectrum 100 transmittance (%) 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 Proton NMR spectrum The numbers by each peak are the relative peak areas. 9 2 3 2 5 4 3 2 1 0 chemical shift, δ / ppm Use the information to identify the organic compound. Show all your reasoning. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [6] Additional answer space if required. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
77. June 2023 · Paper 3 · Q1(h) · 1 marks · AO2
(h) The element with an average atomic mass of 1.244 × 10–22 g. ................... [1]
78. June 2023 · Paper 3 · Q2(a)(ii) · 3 marks · AO2
(ii) A student carries out an experiment to determine the enthalpy change of solution of RbCl O3 using the method below. • A 2.00 g sample of solid RbCl O3 is added to water in a well-insulated container. The initial temperature is 23.0 °C. • The mixture is stirred until all the RbCl O3 has dissolved. The final temperature is 21.5 °C. The final solution has a mass of 102 g. Determine the enthalpy change of solution, ΔsolH, of RbCl O3 in kJ mol–1. Assume that the specific heat capacity of the solution is the same as that of pure water. ΔsolH (RbCl O3) = ........................................... kJ mol–1 [3]
79. June 2023 · Paper 3 · Q4(b)(i) · 2 marks · AO1
(b) A student prepares a sample of the Tutton’s salt, (NH4)2Cu(SO4)2 • 6H2O using the method shown below. Step 1 Dissolve 0.025 mol of ammonium sulfate and 0.025 mol of hydrated copper(II) sulfate, CuSO4 • 5H2O, in water and make up to 50 cm3. Step 2 Boil the resulting mixture for 2 minutes and allow to cool. Step 3 Allow the solvent to evaporate slowly. Pale blue crystals of the Tutton’s salt form. (i) What masses are needed of ammonium sulfate and CuSO4 • 5H2O? mass of ammonium sulfate ............................................................................................ g mass of CuSO4 • 5H2O ................................................................................................... g [2]
80. June 2023 · Paper 3 · Q4(b)(ii) · 1 marks · AO3
(ii) In Step 3, why does the student allow the solvent to evaporate and not boil off all the solvent in Step 2? ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1]
81. June 2023 · Paper 3 · Q5(a) · 6 marks · AO2
5 Aspirin tablets are used for pain relief. The structure of aspirin is shown below. O OH O O Aspirin (a) A student uses the reaction of aspirin with cold NaOH(aq) to determine the mass of aspirin in one tablet. In this reaction, 1 mol of aspirin reacts with 1 mol of cold NaOH(aq). The student’s method is outlined below. Step 1 The student reacts three aspirin tablets with 100 cm3 of 0.500 mol dm–3 NaOH(aq). The NaOH is in excess. A colourless solution forms. Step 2 The colourless solution from Step 1 is made up to 250.0 cm3 with distilled water. Step 3 A 25.00 cm3 sample of the diluted solution from Step 2 is titrated with 0.200 mol dm–3 HCl (aq) in the burette. The HCl (aq) reacts with excess NaOH(aq) that remains in Step 1: NaOH(aq) + HCl (aq) NaCl (aq) + H2O(l) The student repeats the titration to obtain concordant (consistent) titres. Titration results The trial titre has been omitted. The burette readings have been read to the nearest 0.05 cm3. 1 2 3 Final reading / cm3 23.10 45.40 27.40 Initial reading / cm3 0.00 23.10 5.00 Analysis of results From the results, the student can determine the following. 1. The amount, in mol, of excess NaOH(aq) that remains after the reaction of aspirin with NaOH(aq). 2. The amount, in mol, of NaOH(aq) that reacted with the aspirin. Use the results to determine the mass, in mg, of aspirin in one aspirin tablet. mass of aspirin in one tablet = ................................................... mg [6]
82. June 2023 · Paper 3 · Q6(e) · 6 marks · AO3
TURN OVER FOR QUESTION 6 PART (e) (e)* Three reactions involving sulfuric acid are shown below. Reaction 1 Dilute sulfuric acid is reacted with nickel(II) hydroxide to form a green solution. The solvent is allowed to evaporate leaving hydrated crystals of compound D, with the percentage composition by mass: Ni, 22.33%; S, 12.20%; O, 60.87%; H, 4.60%. Reaction 2 Concentrated sulfuric acid is reacted with hydrogen bromide, HBr, to form three products: • an element which exists as diatomic molecules • a gaseous compound E • a liquid. At RTP, 1.00 dm3 of compound E has a mass of 2.67 g. Reaction 3 Concentrated sulfuric acid acts as a catalyst when 2-hydroxypropanoic acid reacts to form compound F (Mr = 144). In this reaction, 2 mol of 2-hydroxypropanoic acid forms 1 mol of compound F and 2 mol of water. Identify compounds D, E and F and construct equations for the reactions. Show structures for any organic compounds. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
83. June 2022 · Paper 1 · Q2 · 1 marks · AO1
2 20 cm3 of nitrogen gas reacts with 10 cm3 of oxygen gas to form 20 cm3 of a gaseous product. Which equation is the most likely for the reaction? A N2(g) + O2(g) 2NO(g) B N2(g) + 2O2(g) N2O4(g) C 2N2(g) + O2(g) 2N2O(g) D 2N2(g) + 2O2(g) 4NO(g) Your answer [1]
84. June 2022 · Paper 1 · Q3 · 1 marks · AO2
3 0.541 g of an element X is reacted with oxygen to form 0.790 g of the oxide X2O3. What is the element X? A Al B Cr C Ga D Sc Your answer [1]
85. June 2022 · Paper 1 · Q4 · 1 marks · AO2
4 Hydrogen peroxide, H2O2, can be oxidised by manganate(VII) ions under acid conditions as shown below. 2MnO4 –(aq) + 5H2O2(aq) + 6H+(aq) 2Mn2+(aq) + 5O2(g) + 8H2O(l) In a titration, 25.00 cm3 of a disinfectant containing hydrogen peroxide reacts with 22.00 cm3 of 0.125 mol dm–3 KMnO4(aq). What is the concentration of H2O2, in mol dm–3, in the disinfectant? Assume that KMnO4 only reacts with H2O2 in the disinfectant. A 0.0440 B 0.110 C 0.275 D 0.550 Your answer [1]
86. June 2022 · Paper 1 · Q5 · 1 marks · AO2
5 The mass of 4 molecules of a substance is 2.125 × 10–22 g. What is the possible formula of the substance? A CH4 B O2 C SO2 D I2 Your answer [1]
87. June 2022 · AS Paper 1 · Q7 · 1 marks · AO2
7 A sample of lead(II) sulfate (M = 303.3 g mol–1) is decomposed by heat, as shown in the equation below. 2PbSO4(s) → 2PbSO3(s) + O2(g) The reaction forms 2.40 g of O2(g). What is the mass of lead(II) sulfate that has been heated? Assume a 100% yield. A 22.7 g B 30.3 g C 45.5 g D 60.7 g Your answer [1]
88. June 2022 · AS Paper 1 · Q8 · 1 marks · AO2
8 Which volume of 18.0 mol dm–3 hydrochloric acid should be diluted to 250.0 cm3 to prepare a 0.450 mol dm–3 solution of hydrochloric acid? A 4.50 cm3 B 6.25 cm3 C 10.0 cm3 D 32.4 cm3 Your answer [1]
89. June 2022 · AS Paper 1 · Q9 · 1 marks · AO2
9 What is the number of ions in 4.00 mol of magnesium chloride, MgCl 2? A 1.81 × 1024 B 2.41 × 1024 C 4.82 × 1024 D 7.22 × 1024 Your answer [1]
90. June 2022 · AS Paper 1 · Q16 · 1 marks · AO2
16 Complete combustion of an alkane forms 30 cm3 of carbon dioxide and 40 cm3 of water vapour, under the same conditions of temperature and pressure. Which alkane has undergone complete combustion? A butane B ethane C heptane D propane Your answer [1]
91. June 2022 · Paper 1 · Q17(a)(i) · 4 marks · AO1, 2
17 This question is about energy changes. (a) Magnesium reacts with aqueous silver nitrate, AgNO3(aq) as shown below. Mg(s) + 2AgNO3(aq) 2Ag(s) + Mg(NO3)2(aq) ∆H = –678 kJ mol–1 A student adds an excess of magnesium to 100.0 cm3 of 0.400 mol dm–3 AgNO3(aq). The initial temperature is 20.0 °C. (i) Determine the maximum temperature reached in this reaction. Give your answer to 3 significant figures. Assume that the specific heat capacity and density of the solution are the same as for water, and that there are no heat losses. maximum temperature reached = .................................................... °C [4]
92. June 2022 · Paper 1 · Q18(b) · 1 marks · AO2
(b) Estimate the energy required to form one Li+(g) ion from one Li(g) atom. Give your answer in kJ, in standard form, and to two significant figures. energy = ..................................................... kJ [1]
93. June 2022 · Paper 1 · Q19(a)(ii) · 5 marks · AO2, 3
(ii) Use the student’s results and Equation 19.1 to calculate the mass, in mg, of succinic acid in one tablet of the health supplement. Give you answer to 3 significant figures. mass = ................................................... mg [5]
94. June 2022 · Paper 1 · Q21(b)(i) · 5 marks · AO2
(b) A sample of barium oxide is added to distilled water at 25 °C. A colourless solution forms containing barium hydroxide, Ba(OH)2. The solution is made up to 250.0 cm3 with distilled water. The pH of this solution is 13.12. (i) Determine the mass of barium oxide that was used. Give your answer to 3 significant figures. mass of barium oxide = ....................................................... g [5]
95. June 2022 · Paper 1 · Q21(c)(i) · 3 marks · AO2
(c) Limestone and huntite are two calcium minerals. (i) A typical sample of limestone contains 95.0% by mass of calcium carbonate, CaCO3. Fertiliser Z, Ca5NH4(NO3)11•10H2O (Mr = 1080.5 g mol–1) can be made from limestone. Calculate the mass, in g, of limestone needed to make 1.50 kg of fertiliser Z. Give your answer to 3 significant figures. mass of limestone = ...................................................... g [3]
96. June 2022 · Paper 1 · Q22(a)(ii) · 4 marks · AO1, 3
(ii) The iron(III) ion, Fe3+, forms a complex ion A with two ethane-1,2-diamine ligands and two chloride ligands. Complex ion A has cis and trans stereoisomers. One of these stereoisomers exists as optical isomers. Determine the empirical formula, with charge, of complex ion A and draw the 3-D structures of the three stereoisomers. Empirical formula with charge .............................. Structures [4]
97. June 2022 · AS Paper 1 · Q22(c) · 3 marks · AO1, 2
(c) Substance A is a hydrated salt with the following percentage composition by mass: Zn, 21.99%; H, 4.04%; N, 9.41%; O, 64.56%. • Determine the empirical formula of A. • Write the formula of A showing the water of crystallisation. empirical formula: ............................................................... formula showing water of crystallisation: ............................................................... [3]
98. June 2022 · Paper 1 · Q22(c) · 6 marks · AO3
TURN OVER FOR QUESTION 22(c) (c)* This question is about copper and copper compounds. Experiment 1 Hydrochloric acid, HCl (aq), is added to an aqueous solution containing [Cu(H2O)6]2+ complex ions. A yellow-green solution forms containing complex ion B. Experiment 2 A piece of copper metal is heated with concentrated sulfuric acid. A reaction takes place forming a pale blue solution C and 45 cm3 of a gas D, measured at RTP. The mass of gas D is 0.12 g. Experiment 3 An excess of copper(II) oxide is heated with dilute nitric acid. The resulting mixture is filtered. The filtrate is a blue solution E. Aqueous potassium iodide, KI(aq), is added to the blue solution E. A white precipitate F and a brown solution G form. Determine the formulae of B–G. Construct equations for the reactions taking place, include any changes in oxidation number, and show your working where appropriate. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
99. June 2022 · AS Paper 1 · Q25(a)(i) · 4 marks · AO2
25 This question is about enthalpy changes and reaction rates. (a) Aqueous barium hydroxide, Ba(OH)2(aq), reacts with dilute nitric acid, HNO3(aq), as in Equation 25.1. Ba(OH)2(aq) + 2HNO3(aq) → Ba(NO3)2(aq) + 2H2O(l) Equation 25.1 A student carries out an experiment to determine the enthalpy change of this reaction, ∆rH. The student measures out: • 25.0 cm3 of 2.00 mol dm–3 Ba(OH)2(aq) and • 50.0 cm3 of 2.00 mol dm–3 HNO3(aq). The temperature of each solution is the same. The student mixes both solutions in a polystyrene cup, stirs the mixture and records the maximum temperature. Temperature readings Initial temperature = 20.5 °C Maximum temperature = 39.0 °C (i) Calculate ∆rH, in kJ mol–1, for the reaction shown in Equation 25.1. Give your answer to 3 significant figures. Assume that the density and specific heat capacity, c, of the solutions are the same as for water. ∆rH = ............................................ kJ mol–1 [4]
100. June 2022 · AS Paper 1 · Q26(b) · 5 marks · AO2, 3
(b) A bromoalkane D is a liquid at room temperature and pressure but can easily be vaporised. When vaporised, 0.330 g of D produces 74.0 cm3 of gas at 1.01 × 105 Pa and 100 °C. Determine the molar mass and molecular formula of bromoalkane D. molar mass = .................................................. g mol−1 molecular formula = ............................................................... [5]
101. June 2022 · AS Paper 2 · Q1(b)(ii) · 5 marks · AO2
(ii) Citric acid, C6H8O7, is neutralised by NaOH as shown in the equation below. C6H8O7 + 3NaOH Na3C6H5O7 + 3H2O Calculate the mass, in g, of citric acid in one lime. Assume that citric acid (Mr = 192.0) is the only acid in lime juice. mass of citric acid in one lime = ...................................................... g [5]
102. June 2022 · AS Paper 2 · Q1(c) · 2 marks · AO3
(c) The student’s teacher thinks that there is an unnecessary safety risk in using a sodium hydroxide concentration of 0.800 mol dm–3 for the titration. Suggest how the student could modify the method using a sodium hydroxide concentration of 0.200 mol dm–3 instead of 0.800 mol dm–3. The student should aim to have the same titre as in the original method. Justify your answer. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [2]
103. June 2022 · AS Paper 2 · Q5(b) · 2 marks · AO1, 2
(b) 2-Bromobutane can also be prepared by reacting but-2-ene, CH3CH=CHCH3, with hydrogen bromide, HBr (Reaction 5.2). CH3CH=CHCH3 + HBr CH3CH2CHBrCH3 Reaction 5.2 Explain, in terms of atom economy, why Reaction 5.2 is more sustainable than Reaction 5.1. Include calculations to justify your answer. ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [2]
104. June 2022 · AS Paper 2 · Q5(c)(i) · 3 marks · AO2
(c) 2-Bromobutane can also be prepared by reacting butan-2-ol, CH3CH2CHOHCH3, with sodium bromide and sulfuric acid (Reaction 5.3). CH3CH2CHOHCH3 + H+ + Br– CH3CH2CHBrCH3 + H2O Reaction 5.3 2-Bromobutane is a liquid with a boiling point of 91 °C and does not mix with water. (i) A student plans to prepare 10.0 g of 2-bromobutane using Reaction 5.3. The percentage yield is 67.0%. Calculate the mass of CH3CH2CHOHCH3 needed for this preparation. Give your answer to 3 significant figures. mass = ...................................................... g [3]
105. June 2022 · Paper 2 · Q6 · 1 marks · AO1
6 Which process has the highest atom economy for preparing ethene, C2H4? In each process, assume that ethene is the only product that is used. A C10H22 3C2H4 + C4H10 B C6H14 2C2H4 + C2H6 C C2H5Cl C2H4 + HCl D C2H5OH C2H4 + H2O Your answer [1]
106. June 2022 · Paper 2 · Q7 · 1 marks · AO1
7 Complete combustion of 0.050 mol of an alkane produces 5.40 g of H2O. What is the molecular formula of the alkane? A C2H6 B C3H8 C C4H10 D C5H12 Your answer [1]
107. June 2022 · Paper 2 · Q8 · 1 marks · AO2
8 The structure of the painkiller, paracetamol, is shown below. OH O N H paracetamol A tablet contains 3.31 × 10–3 mol of paracetamol. What is the mass of paracetamol in the tablet? A 493 mg B 497 mg C 500 mg D 506 mg Your answer [1]
108. June 2022 · Paper 2 · Q9 · 1 marks · AO2
9 The compound below reacts with hydrogen gas to form a saturated compound. CN What is the volume of hydrogen, measured at room temperature and pressure, that reacts with 0.0500 mol of the compound? A 2.40 dm3 B 3.60 dm3 C 4.80 dm3 D 6.00 dm3 Your answer [1]
109. June 2022 · Paper 2 · Q17 · 6 marks · AO1, 2
17 This question is about an analysis of an unknown organic Compound X. Some properties of Compound X are shown in the table. Molecular formula Functional groups Chirality C–F CxHyF6O 1 chiral carbon C–O–C At a pressure of 1.07 × 105 Pa at 30 °C, 1.327 g of Compound X is a gas with a volume of 186 cm3. Determine the molar mass of Compound X and its molecular formula. Draw a possible structure for a molecule of Compound X. molar mass ................................................... g mol–1 molecular formula ............................................................... Structure of Compound X [6]
110. June 2022 · Paper 2 · Q18(b) · 4 marks · AO1, 2, 3
(b) A student is provided with two unknown carbonyl compounds, F and G. The compounds are analysed and found to have identical percentage compositions by mass: C: 62.07%; H: 10.34%; O: 27.59% The mass spectra of the two compounds are shown below. Mass spectrum of F 100 80 60 Relative intensity 40 20 0 10 15 20 25 30 35 40 45 50 55 60 65 70 75 m / z Mass spectrum of G 100 80 60 Relative intensity 40 20 0 10 15 20 25 30 35 40 45 50 55 60 m / z Use the results to identify the structures of the two compounds. Include relevant peaks present in the mass spectrum of each compound. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... F G [4]
111. June 2022 · Paper 2 · Q19(e) · 6 marks · AO3
(e)* A student intends to synthesise compound I. O O NH2 Compound I Plan a synthesis to prepare 9.36 g of compound I starting from 2-chloropropanoic acid, CH3CHCl COOH. The overall percentage yield of compound I from 2-chloropropanoic acid is 64%. In your answer, include starting mass of 2-chloropropanoic acid, reagents, conditions and equations where appropriate. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
112. June 2022 · Paper 3 · Q2(a)(i) · 3 marks · AO2
2 This question is about redox reactions. (a) ‘Calcium hypochlorite’, Ca(Cl O)2, is an ionic compound used in ‘bleaching powder’. The Cl O– ion in Ca(Cl O)2 is the active ingredient that kills bacteria. Calcium hypochlorite is prepared by reacting chlorine gas with calcium hydroxide. 2Cl 2(g) + 2Ca(OH)2(s) Ca(Cl O)2(s) + CaCl 2(s) + 2H2O(l) Equation 2.1 (i) 420 dm3 of chlorine, measured at RTP, is reacted with an excess of Ca(OH)2. The solid products are dissolved in water to form 4.00 m3 of solution. Calculate the concentration of Ca(Cl O)2(aq) in this solution, in mol dm–3. Give your answer to an appropriate number of significant figures and in standard form. concentration = .......................................... mol dm–3 [3]
113. June 2022 · Paper 3 · Q3(a) · 6 marks · AO2, 3
3 Information about 1-bromobutane and butan-1-ol is shown in the table. Compound Melting point / °C Boiling point / °C Density / g cm–3 1-bromobutane –113 102 1.268 butan-1-ol –90 118 0.810 A student prepares a sample of 1-bromobutane by refluxing 9.25 g of butan-1-ol with sodium bromide and sulfuric acid. After reflux, the reaction mixture is purified. The student obtains 6.10 cm3 of pure 1-bromobutane. (a)* Draw a diagram to show how the student would have carried out the reflux and calculate the percentage yield of 1-bromobutane that the student obtains. Describe how the student could have obtained pure 1-bromobutane from the reaction mixture obtained after reflux. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
114. June 2022 · Paper 3 · Q5(b)(ii) · 3 marks · AO2
(ii) Calculate the energy released, in kJ, by the complete combustion of 8.00 kg of this fuel. ∆cH(C8H18) = –5470 kJ mol–1; ∆cH(C2H5OH) = –1367 kJ mol–1. energy released = ..................................................... kJ [3]
115. June 2022 · Paper 3 · Q6(b)(ii) · 2 marks · AO3
(ii) A ‘vitamin C ester’ tablet contains an ester with the molecular formula C22H38O7. This ester can be prepared by reacting vitamin C with a long chain carboxylic acid, CxHyCOOH, in the presence of an acid catalyst. Vitamin C and the long chain carboxylic acid react in a 1:1 molar ratio. Determine x and y in the formula of this carboxylic acid. x = .............. y = .............. [2]
116. June 2022 · Paper 3 · Q6(c)(ii) · 3 marks · AO1, 2
(ii) The student dissolves 0.150 mol of vitamin C in water and makes the solution up to 250 cm3 in a volumetric flask. Calculate the pH of this solution of vitamin C. Give your answer to 2 decimal places. pH = ......................................................... [3]
117. June 2022 · Paper 3 · Q6(d) · 4 marks · AO2
TURN OVER FOR QUESTION 6 PART (d) (d) The label on a carton of orange juice lists the mass of vitamin C, in mg, in a typical serving of 150 cm3. The student carries out an investigation to check the vitamin C content in the orange juice. Vitamin C can be oxidised by iodine: C6H8O6(aq) + I2(aq) C6H6O6(aq) + 2I–(aq) + 2H+(aq) The student dilutes 150 cm3 of the orange juice with water to 250.0 cm3 in a volumetric flask. The student then titrates 25.0 cm3 volume of this solution with 9.60 × 10–4 mol dm–3 iodine solution, I2(aq). The mean titre of I2(aq) is 22.50 cm3. Determine the mass, in mg, of vitamin C in a 150 cm3 serving of the orange juice. mass of vitamin C in the 150 cm3 serving of orange juice = ................................................... mg [4]
118. November 2021 · AS Paper 1 · Q4 · 1 marks · AO1
4 Which alkane is 82.8% carbon by mass? A CH4 B C2H6 C C4H10 D C8H18 Your answer [1]
119. November 2021 · Paper 1 · Q4 · 1 marks ·
4 Which sample contains the greatest number of molecules? A 140.0 g C2H2 B 180.0 g C2H6 C 240.0 g C4H10 D 400.0 g C6H6 Your answer [1]
120. November 2021 · AS Paper 1 · Q5 · 1 marks · AO2
5 Which gas sample has the greatest mass at RTP? A 50 cm3 of Ar(g) B 100 cm3 of O2(g) C 150 cm3 of N2(g) D 200 cm3 of Ne(g) Your answer [1]
121. November 2021 · Paper 1 · Q5 · 1 marks ·
5 Chromium(III) oxide, Cr2O3, is reduced to chromium by heating with magnesium. What is the minimum mass of Mg required to reduce 11.4 g of chromium(III) oxide? A 0.61 g B 0.91 g C 3.65 g D 5.47 g Your answer [1]
122. November 2021 · AS Paper 1 · Q6 · 1 marks · AO2
6 A student mixes 250.0 cm3 of 0.100 mol dm–3 KOH with 750.0 cm3 of 0.100 mol dm–3 Ca(OH)2. What is the OH– concentration, in mol dm–3, in the resulting mixture? A 0.0250 B 0.100 C 0.150 D 0.175 Your answer [1]
123. November 2021 · Paper 1 · Q6 · 1 marks ·
6 A student is supplied with 100.0 cm3 of a solution of 0.400 mol dm–3 magnesium iodide, MgI2. A student plans to dilute this solution so that the iodide concentration is 0.250 mol dm–3. What volume of water, in cm3, does the student need to add? A 60.0 B 160.0 C 220.0 D 320.0 Your answer [1]
124. November 2021 · Paper 1 · Q17(b)(ii) · 6 marks · AO2, 3
(ii)* Determine the formulae of A and B. Write the ionic equation for the ligand substitution and show 3D structures for the three stereoisomers of B. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [6] Additional answer space if required. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...........................................................................................................................................
125. November 2021 · Paper 1 · Q18(d) · 4 marks · AO2
(d) Determine the percentage, by mass, of copper in the copper ore. Give your answer to an appropriate number of significant figures. percentage = ..................................................... % [4]
126. November 2021 · AS Paper 1 · Q21(d)(ii) · 2 marks · AO2
(ii) What is the number of fluorine atoms in 7.896 g of halothane, C2HBrCl F3? number of fluorine atoms = ......................................................... [2]
127. November 2021 · Paper 1 · Q22(b)(i) · 2 marks · AO2
(b) Sulfuric acid reacts with sodium hydroxide as shown in Equation 22.1. Equation 22.1 H2SO4(aq) + 2NaOH(aq) → Na2SO4(aq) + 2H2O(l) ΔH1 This is a neutralisation reaction. A student carries out an experiment to determine the enthalpy change ΔH1 and uses this value to deduce the enthalpy change of neutralisation, ΔneutH . The student measures out two solutions: • 25.0 cm3 of 1.60 mol dm–3 H2SO4(aq) • 55.0 cm3 of 1.50 mol dm–3 NaOH(aq) (an excess). The temperature of each solution is the same. The student mixes the two solutions. The temperature increases by 13.0 °C. (i) Show that NaOH is in excess. [2]
128. November 2021 · Paper 1 · Q22(c) · 6 marks · AO1, 2, 3
(c)* Nitrous acid, HNO2, is a weak Brønsted–Lowry acid with a pKa value of 3.34 at room temperature. HNO2 can be prepared by reacting N2O3 with water. HNO2 is the only product. A chemist makes up a buffer solution by the following method. Step 1 The chemist weighs a sample of N2O3. Water is then added to form 100 cm3 of 0.500 mol dm–3 HNO2(aq). Step 2 The chemist adds 100 cm3 of 0.150 mol dm–3 NaOH(aq) to the 100 cm3 solution of 0.500 mol dm–3 solution of HNO2(aq). The resulting solution is made up to 1.00 dm3. Explain why a buffer solution forms in Step 2. Determine the pH of this buffer solution and the mass of N2O3 that was used in Step 1. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [6] Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
129. November 2021 · AS Paper 1 · Q25(a)(i) · 2 marks · AO2
25 This question is about the analysis of unknown compounds. (a) Scandium (atomic number 21) reacts with oxygen to form an oxide of scandium. A student carries out an experiment to determine the empirical formula of the scandium oxide. A diagram of the apparatus used by the student is shown below. crucible pipeclay triangle The student’s method is outlined below. • Weigh an empty crucible. • Add scandium to the crucible and reweigh. • Heat the crucible and contents for 10 minutes. • Allow to cool and reweigh. The student’s results are shown below. Mass of crucible / g 12.165 Mass of crucible + scandium / g 12.435 Mass of crucible + scandium oxide / g 12.579 (i) Determine the empirical formula of the scandium oxide. empirical formula = ......................................................... [2]
130. November 2021 · AS Paper 1 · Q25(a)(ii) · 1 marks · AO3
(ii) The student was unsure that all of the scandium had reacted. Suggest one modification that the student could make to their method to be confident that all the scandium had reacted. Explain your reasoning. ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1]
131. November 2021 · AS Paper 1 · Q25(b) · 5 marks · AO1, 2, 3
(b) A gas cylinder has a gas volume of 9.39 dm3. The gas cylinder holds 1.69 kg of a gas at a pressure of 1.37 × 107 Pa at 20 °C. Determine the molar mass and possible identity of the gas. molar mass = .................................................. g mol−1 identity of gas = ............................................................... [5]
132. November 2021 · Paper 2 · Q3 · 1 marks ·
3 Which sample contains the greatest number of carbon atoms? A 20.0 g C6H5OH B 30.0 g C2H5COOH C 40.0 g CH3CHO D 50.0 g CH3OH Your answer [1]
133. November 2021 · AS Paper 2 · Q3(c) · 5 marks · AO2, 3
(c) Calculate the value of n in HOOC(CH2)nCOOH. Give your answer to the nearest whole number. n = .......................................................... [5]
134. November 2021 · AS Paper 2 · Q4(a) · 6 marks · AO3
4 A student carries out an investigation to find the enthalpy change for the decomposition of magnesium carbonate, ∆H1 (Reaction 1). Reaction 1 MgCO3(s) MgO(s) + CO2(g) ∆H1 This enthalpy change cannot be found directly. It can be determined indirectly from the enthalpy changes for the reactions below, which can be found by experiment. Reaction 2 MgCO3(s) + 2HCl (aq) MgCl 2(aq) + H2O(l) + CO2(g) ∆H2 Reaction 3 MgO(s) + 2HCl (aq) MgCl 2(aq) + H2O(l) ∆H3 The enthalpy cycle is shown in Fig. 4.1. Reaction 1 MgCO3(s) MgO(s) + CO2(g) ΔH1 Reaction 2 ΔH2 ΔH3 Reaction 3 MgCl2(aq) + H2O(l) + CO2(g) Fig. 4.1 Determination of ∆H2 for Reaction 2 Student’s method • Weigh a 250 cm3 polystyrene cup. • Add about 100 cm3 of 2.00 mol dm–3 hydrochloric acid (an excess) to the polystyrene cup and record the initial temperature of the HCl (aq). • Add 4.215 g MgCO3, stir the mixture, and record the final temperature. • Weigh the polystyrene cup containing the final solution. Results Mass of polystyrene cup / g 21.415 Mass of polystyrene cup + final solution / g 124.425 Initial temperature of HCl (aq) / °C 20.40 Final temperature of solution / °C 25.40 Determination of ∆H3 for Reaction 3 The student uses the same method as for Reaction 2 but with MgO in place of MgCO3. The student calculates ∆H3 for Reaction 3 as –136.1 kJ mol–1. (a)* Use the student’s results to calculate ∆H2 for Reaction 2 and determine the enthalpy change ∆H1, in kJ mol–1, for the decomposition of magnesium carbonate (Reaction 1), using the energy cycle in Fig. 4.1. Assume the specific heat capacity, c, of the reaction mixture is the same as for water. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [6]
135. November 2021 · AS Paper 2 · Q6(c)(i) · 2 marks · AO3
(c) A third student repeats the original experiment using the same amount, in moles, of barium as strontium. (i) Calculate the mass of barium that the student uses. Give your answer to 2 decimal places. mass of barium = ...................................................... g [2]
136. November 2021 · AS Paper 2 · Q7(b) · 6 marks · AO1, 2, 3
(b)* The student’s method for the preparation is outlined below. • Add 10.0 cm3 (7.70 g) of (CH3)3COH and 30 cm3 concentrated hydrochloric acid (an excess) to a round-bottom flask. Stopper the flask. • Shake the flask until the mixture separates into two layers. Densities: (CH3)3CCl : 0.85 g cm–3; concentrated HCl : 1.18 g cm–3 After purification, the percentage yield of (CH3)3CCl is 76%. Explain how the student could obtain a pure, dry sample of (CH3)3CCl from the mixture in the flask and calculate the mass of pure (CH3)3CCl that would be expected from this preparation. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [6]
137. November 2021 · Paper 2 · Q18(c)(i) · 1 marks · AO2
(c) Ibuprofen, shown below, is used as a painkiller. O OH ibuprofen (i) What is the molecular formula of ibuprofen? ...................................................................................................................................... [1]
138. November 2021 · Paper 2 · Q18(c)(ii) · 3 marks · AO2
(ii) One ibuprofen tablet contains 400 mg of ibuprofen. Calculate the number of ibuprofen molecules in one ibuprofen tablet. Give your answer to 3 significant figures. number of ibuprofen molecules = ......................................................... [3]
139. November 2021 · Paper 2 · Q19(b) · 6 marks · AO2, 3
(b)* A student intends to synthesise compound A using the two-stage route below. O Stage 1 Stage 2 CH2 Cl Intermediate CH2 C OH (chloromethyl)benzene Compound A Plan a two-stage synthesis to prepare 5.44 g of compound A starting from (chloromethyl)benzene, C6H5CH2Cl . Assume that the overall percentage yield of compound A from (chloromethyl)benzene is 25%. In your answer, include the mass of C6H5CH2Cl required, reagents, and equations where appropriate. Purification details are not required. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
140. November 2021 · Paper 2 · Q20(b)(ii) · 6 marks · AO1, 3
(ii) The pure sample of C is analysed to give the following results. Percentage composition by mass: C, 31.44%; H, 1.31%; N, 18.34%; O, 48.91%. The mass spectrum of C shows a molecular ion peak at m /z = 229.0 The 13C NMR spectrum of C is shown below. 160 140 120 100 80 60 40 20 0 chemical shift, δ / ppm The table shows directing effects for different groups in the electrophilic substitution of aromatic compounds. Directing effect 2- and 4- directing 3-directing –OH –NO2 Group –NH2 Analyse all the information to suggest the structure for C. Show all your reasoning. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... compound C [6]
141. November 2021 · Paper 3 · Q1(a) · 2 marks · AO1
1 These short questions are from different areas of chemistry. (a) A flask contains 110 g CO2 and 120 g O2 at a pressure of 50.0 atm. What is the partial pressure of the CO2? partial pressure of CO2 = .................................................. atm [2]
142. November 2021 · Paper 3 · Q1(d) · 4 marks · AO1, 2
(d) Compound A has the following percentage composition by mass: Ca, 81.10%; N, 18.90%. A student reacts compound A with water to form alkaline gas B and alkali C. Identify A, B and C and write the equation for the reaction of compound A with water. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [4]
143. November 2021 · Paper 3 · Q2(a) · 2 marks · AO3
2 Europium (Ar = 152.0) reacts with dilute aqueous acid in a redox reaction, forming a solution and hydrogen gas. A student proposed three possible ionic equations for this reaction, forming europium ions with different charges: Equation 1 2Eu(s) + 2H+(aq) 2Eu+(aq) + H2(g) Equation 2 Eu(s) + 2H+(aq) Eu2+(aq) + H2(g) Equation 3 2Eu(s) + 6H+(aq) 2Eu3+(aq) + 3H2(g) The student plans to carry out an investigation to determine which equation is correct. Hydrochloric acid is used as the source of H+(aq) ions. The student’s method is outlined below. Step 1 Using a 3 decimal place balance, weigh a suitable container for the reaction. Add about 1 g of europium to the container and reweigh. Step 2 Set up apparatus for gas collection. Add an excess of dilute hydrochloric acid to the europium. Step 3 Measure the volume of gas produced. Results Mass of container = 32.795 g Mass of container + europium = 33.783 g Volume of gas collected = 152 cm3 (a) Draw a labelled diagram of suitable apparatus for this investigation. [2]
144. November 2021 · Paper 3 · Q2(b) · 3 marks · AO2, 3
(b) Analyse the student’s results to conclude which of Equation 1 or 2 or 3, is supported by the experimental results. Assume that the conditions in the laboratory are ‘room temperature and pressure’ (RTP). correct equation (1, 2, or 3) = ................ [3]
145. November 2021 · Paper 3 · Q2(d) · 2 marks · AO3
(d) The student modifies their method as outlined below: • 1.52 g (0.01 mol) of europium is reacted with an excess of dilute hydrochloric acid. • An excess of aqueous sodium hydroxide is added to the reaction mixture. • A precipitate forms which is collected, dried and weighed. Explain how the mass of precipitate formed would allow the student to conclude which of Equation 1 or 2 or 3 is correct. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [2]
146. November 2021 · Paper 3 · Q3(a) · 5 marks · AO1, 2
3 This question is about carboxylic acids. Compound D is a cis stereoisomer of an unsaturated organic acid with the general formula CnH2n–1COOH. A student plans to analyse acid D by carrying out a titration. (a) A student first prepares 250.0 cm3 of a standard solution of 0.150 mol dm–3 Ba(OH)2 for the titration. The student is provided with solid Ba(OH)2 and usual laboratory apparatus and equipment. Describe how the student would prepare the standard solution, giving full details of quantities, apparatus and method. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [5]
147. November 2021 · Paper 3 · Q3(b) · 7 marks · AO2, 3
(b) The student prepares a 100.0 cm3 solution containing 3.215 g of acid D. The student titrates 25.0 cm3 samples of the solution of D with 0.150 mol dm–3 Ba(OH)2(aq) in the burette. 1 mol Ba(OH)2 reacts with 2 mol of D. The mean titre of Ba(OH)2(aq) is 23.50 cm3. Analyse the titration results to determine two possible structures for the cis stereoisomer of organic acid D. Structures of 2 possible cis stereoisomers of acid D [7]
148. November 2021 · Paper 3 · Q5(a)(ii) · 5 marks · AO2
(ii) A 16.0 dm3 airbag is inflated at 17.0 ºC. The pressure in the inflated airbag is 1.20 × 105 Pa. Calculate the mass of NaN3 that has decomposed. Give your answer to 3 significant figures. mass of NaN3 = ...................................................... g [5]
149. November 2021 · Paper 3 · Q5(c) · 6 marks · AO3
(c)* This question is about two reactions of ammonia. Reaction 1 Excess ammonia is reacted with 4.77 g of copper(II) oxide. The reaction produces 3.81 g of solid E, liquid F and 0.560 g of gas G, which has a volume of 480 cm3 at RTP. Reaction 2 Ammonia reacts with compound H to form compound I, C2H5NO, and chloride salt J. The IR spectrum of I is shown below. 100 transmittance 50 (%) 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 Identify E, F, G, H, I and J, and write equations for the two reactions. Show your reasoning. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
150. November 2020 · Paper 1 · Q2 · 1 marks · AO1
2 Which statement gives the numerical value of the Avogadro constant? A The number of moles in 12 g of carbon-12. B The number of electrons lost by 20.05 g of calcium when it reacts with oxygen. C The number of molecules in 16.0 g of oxygen. D The number of atoms in 1 mole of chlorine molecules. Your answer [1]
151. November 2020 · Paper 1 · Q3 · 1 marks · AO2
3 0.80 g of element X is reacted with 0.40 g of O2 to form an oxide with the formula X2O3. What is the identity of element X? A Aluminium B Titanium C Germanium D Molybdenum Your answer [1]
152. November 2020 · Paper 1 · Q4 · 1 marks · AO2
4 Phosphoric acid is a tribasic acid. What is the mass of Ca(OH)2 that completely neutralises 100 cm3 of 0.100 mol dm−3 phosphoric acid? A 0.49 g B 0.74 g C 1.11 g D 2.22 g Your answer [1]
153. November 2020 · AS Paper 1 · Q9 · 1 marks · AO2
9 2.0 dm3 of Cl 2 gas reacts with 2.0 dm3 of Cl F3 gas to form 6.0 dm3 of a gaseous compound. The reaction has 100% atom economy and all volumes are measured at the same temperature and pressure. What is the molecular formula of the compound formed? A Cl F B Cl 2F3 C Cl 3F2 D Cl 3F3 Your answer [1]
154. November 2020 · AS Paper 1 · Q10 · 1 marks · AO2
10 Which sample contains the greatest number of molecules? A 1 g of methanol, CH3OH B 2 g of nitrogen dioxide, NO2 C 3 g of phosphorus, P4 D 4 g of iodine, I2 Your answer [1]
155. November 2020 · Paper 1 · Q11 · 1 marks · AO2
11 20 cm3 of 0.10 mol dm−3 hydrochloric acid is added to 10 cm3 of 0.10 mol dm−3 sodium hydroxide. What is the pH of the resulting mixture? A 1.00 B 1.18 C 1.30 D 1.48 Your answer [1]
156. November 2020 · AS Paper 1 · Q14 · 1 marks · AO1
14 Which statement is correct for the two structures below? A They have the same empirical formula. B They have different relative molecular masses. C They are structural isomers. D They have different functional groups. Your answer [1]
157. November 2020 · Paper 1 · Q16(b)(ii) · 3 marks · AO2
(ii) Calculate the total number of ions in 1.74 g of magnesium bromide, MgBr2. Give your answer to 3 significant figures. number of ions = ......................................................... [3]
158. November 2020 · AS Paper 1 · Q18 · 1 marks · AO2
18 A student reacts 24.24 g of 2-bromobutane in the reaction below. CH3CH2CHBrCH3 + NaOH → CH3CH2CHOHCH3 + NaBr Mr = 136.9 Mr = 74.0 The reaction produces 4.81 g of CH3CH2CHOHCH3. What is the percentage yield of CH3CH2CHOHCH3? A 10.7% B 19.8% C 36.7% D 54.1% Your answer [1]
159. November 2020 · Paper 1 · Q20(b) · 4 marks · AO1, 2
(b) The student carries out a second experiment to determine the value of Kc for this reaction. The student mixes 9.6 g of CH3OH with 12.0 g of CH3COOH and adds the acid catalyst. When the mixture reaches equilibrium, 0.030 mol of CH3COOH remains. Calculate Kc for this equilibrium. Kc = ......................................................... [4]
160. November 2020 · Paper 1 · Q21(c) · 3 marks · AO2, 3
(c) Compound A contains bromine and fluorine only, and has a boiling point of 41 °C. 1.26 g of compound A is heated to 80 °C. The volume of gas produced is 0.209 dm3. Under the conditions used, 1 mol of gas molecules has a volume of 29.0 dm3. Determine the molecular formula of compound A. molecular formula = ......................................................... [3]
161. November 2020 · Paper 1 · Q22(b)(i) · 3 marks · AO3
(b) A compound of nickel, J, has the formula (NH4)2 [Ni(SCN)x(NH3)y] and contains SCN− and NH3 ligands. The percentage by mass of three of the elements in compound J is shown below: Ni, 16.26%; S, 35.56%; N, 31.00%. (i) Calculate the values of x and y in the formula of compound J. x = ............................................................... y = ............................................................... [3]
162. November 2020 · AS Paper 1 · Q22(c) · 5 marks · AO2, 3
(c) Bromine reacts with fluorine to form compound A. Compound A is a liquid at room temperature and pressure but can easily be vaporised. When vaporised, 0.428 g of A produces 76.0 cm3 of gas at 1.00 × 105 Pa and 100 °C. Determine the molar mass and molecular formula of compound A. molar mass of A = .................................................. g mol−1 molecular formula of A = ............................................................... [5]
163. November 2020 · Paper 1 · Q22(c) · 5 marks · AO1, 2, 3
(c) Sodium sulfite(IV), Na2SO3, is used as a preservative in some foods. Food safety legislation allows a maximum of 850 mg Na2SO3 per kg of burger meat. A chemist determines the amount of Na2SO3 in a sample of burger meat using a manganate(VII) titration. Step 1 The Na2SO3 from 525 g of burger meat is extracted to form a solution containing SO3 2−(aq) ions. Step 2 The solution from step 1 is made up to 250.0 cm3 in a volumetric flask with water. 25.0 cm3 of this diluted solution is pipetted into a conical flask. Step 3 The pipetted solution from step 2 is acidified with dilute sulfuric acid and then titrated with 0.0100 mol dm−3 potassium manganate(VII), KMnO4. 2MnO4 −(aq) + 6H+(aq) + 5SO3 2−(aq) 2Mn2+(aq) + 3H2O(l) + 5SO4 2−(aq) 12.60 cm3 of KMnO4(aq) is required to reach the endpoint. Analyse the results to determine whether the burger meat complies with food safety legislation. [5]
164. November 2020 · AS Paper 1 · Q23(a) · 3 marks · AO3
23 This question is about barium hydroxide. (a) Barium hydroxide is an alkali which releases hydroxide ions, OH−, in aqueous solution. A barium hydroxide solution contains 3.89 g of Ba(OH)2 in 100 cm3 at 20 °C. Calculate the concentration of hydroxide ions, OH−, in mol dm−3, of this solution at 20 °C. Give your answer to 3 significant figures. concentration of OH− ions = .......................................... mol dm−3 [3]
165. November 2020 · AS Paper 1 · Q23(b)(ii) · 3 marks · AO2
(ii) Calculate the concentration, in mol dm−3, of the Ba(OH)2(aq) solution. concentration of Ba(OH)2(aq) = .......................................... mol dm−3 [3]
166. November 2020 · AS Paper 2 · Q1(b)(i) · 3 marks · AO1, 2
(b) A student completely reacts 0.192 g of nickel with 0.150 mol dm–3 HCl (aq). (i) Calculate the minimum volume, in cm3, of 0.150 mol dm–3 HCl (aq) that the student needs for the reaction. Give your answer to 3 significant figures. minimum volume of HCl (aq) = .................................................. cm3 [3]
167. November 2020 · AS Paper 2 · Q1(b)(ii) · 1 marks · AO2
(ii) Calculate the volume of H2(g), in cm3, that would be produced at RTP. volume of H2(g) = .................................................. cm3 [1]
168. November 2020 · AS Paper 2 · Q1(b)(iii) · 2 marks · AO3
(iii) The student repeats the experiment with 0.192 g of magnesium instead of nickel, using the same volume of 0.150 mol dm–3 HCl (aq) as in (b)(i). State and explain whether the volume of H2(g) produced would be greater than, smaller than, or the same as, the value you have calculated in (b)(ii). ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2]
169. November 2020 · AS Paper 2 · Q2(b) · 4 marks · AO1, 3
(b) A student carries out an experiment to determine the enthalpy change of combustion of cyclohexane, C6H12, using the apparatus shown in the diagram. thermometer beaker clamp 200 cm3 water wick spirit burner cyclohexane In the experiment, 0.525 g of cyclohexane are burnt, and the temperature of the 200 cm3 of water changes from 21.0 °C to 41.0 °C. Calculate the enthalpy change of combustion, ΔcH, of cyclohexane in kJ mol−1. Give your answer to 3 significant figures. ΔcH = ............................................ kJ mol–1 [4]
170. November 2020 · AS Paper 2 · Q4(b)(ii) · 1 marks · AO3
(ii) In the equilibrium mixture at 400 °C, the equilibrium concentration of Cl 2(g) is found to be 0.17 mol dm−3. The student calculates that the equilibrium concentration of NO(g) is 0.34 mol dm−3. Explain how the student obtained this value for [NO(g)]. ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1]
171. November 2020 · AS Paper 2 · Q5(d)(i) · 2 marks · AO1, 2
(d) Alcohol A can be prepared by the alkaline hydrolysis of the bromoalkane, (CH3)2CHCH2CH2Br. The hydrolysis with aqueous NaOH is shown in equation 5.1. (CH3)2CHCH2CH2Br + NaOH (CH3)2CHCH2CH2OH + NaBr equation 5.1 alcohol A A student gently heats a mixture of (CH3)2CHCH2CH2Br and NaOH(aq) for 25 minutes. (i) Calculate the atom economy for the preparation of alcohol A in equation 5.1. atom economy = ..................................................... % [2]
172. November 2020 · Paper 2 · Q11 · 1 marks · AO2
11 Complete combustion of 1.00 g of a hydrocarbon gives 3.38 g carbon dioxide. What is the empirical formula of the hydrocarbon? A CH B CH2 C C2H5 D C3H8 Your answer [1]
173. November 2020 · Paper 2 · Q12 · 1 marks · AO2
12 What is the molecular formula of the steroid molecule below? OH HO A C18H24O2 B C18H26O2 C C18H28O2 D C18H30O2 Your answer [1]
174. November 2020 · Paper 2 · Q20(a) · 6 marks · AO2, 3
20 Cyclopentanol can be reacted to form cyclopentene. Cyclopentene is a liquid with a boiling point of 44 °C and a density of 0.74 g cm−3. A student plans to prepare 4.00 g of cyclopentene by reacting cyclopentanol (boiling point 140 °C) with an acid catalyst. Equation OH + H2O The expected percentage yield of cyclopentene is 64.0%. Method The student carries out the preparation using apparatus set up for distillation, as shown below. 1 The reaction mixture is heated gently, and a distillate containing impure cyclopentene is collected. cyclopentanol and water concentrated out phosphoric acid water in water bath distillate ice-water mixture 2 The distillate has an aqueous layer and an organic layer. The student purifies the cyclopentene from the distillate. (a)* Calculate the mass of cyclopentanol that the student should use and explain how pure cyclopentene could be obtained from the distillate. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
175. November 2020 · Paper 2 · Q21(b)(iii) · 3 marks · AO2
(iii) Some people are concerned that aspartame, C14H18N2O5, may have adverse health effects. Research shows that the safe maximum daily intake of aspartame is 1.7 × 10−4 mol kg−1. • A typical UK adult has a mass of 75 kg. • A can of a diet drink contains 167 mg of aspartame. How many cans of this diet drink is it safe for a typical adult to drink in one day? Number of cans = .......................................................... [3]
176. November 2020 · Paper 2 · Q22(b) · 6 marks · AO3
(b)* Determine the structure of compound I, showing all your reasoning. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
177. November 2020 · Paper 3 · Q1(b)(ii) · 6 marks · AO2, 3
(ii) Amine A is a liquid at room temperature and pressure. When vaporised, 0.202 g of the amine produces 72.0 cm3 of gas at 1.00 × 105 Pa and 100 °C. The 13C NMR spectrum of amine A has 3 peaks. Determine the molecular formula of A and suggest a possible structure for amine A. Molecular formula of A ............................................................... Structure of A [6]
178. November 2020 · Paper 3 · Q3(a)(i) · 3 marks · AO2
3 Propane, C3H8, (boiling point −42 °C) is used as ‘camping gas’. A student plans to determine the enthalpy change of combustion of propane, ∆cH (C3H8), by two methods. (a) The student first carries out an experiment using the apparatus below. thermometer beaker 100 cm3 water clamp propane burner Results Mass of propane burner before burning / g 99.218 Mass of propane burner after burning / g 98.976 Initial temperature / °C 21.60 Maximum temperature reached / °C 46.10 (i) Determine the enthalpy change of combustion of propane, in kJ mol−1. Give your answer to 3 significant figures. ∆cH (C3H8) = ........................................... kJ mol−1 [3]
179. November 2020 · Paper 3 · Q4(a)(iv) · 6 marks · AO2, 3
(iv) Metal M can be identified following the steps below. 1. The amount, in mol, of excess HCl (aq) that remains after the reaction of M with HCl (aq). 2. The amount, in mol, of HCl (aq) that reacted with M. 3. The identity of metal M. Analyse the results to identify metal M. Metal M = .......................................................... [6]
180. November 2020 · Paper 3 · Q4(b)(i) · 1 marks · AO2
(b) The student is provided with the carbonate of an unknown metal, X2CO3. The student measures the mass loss when the X2CO3 is reacted with an excess of hydrochloric acid. The equation is shown below. X2CO3(s) + 2HCl (aq) → 2XCl (aq) + CO2(g) + H2O(l) The reaction is carried out using this method: Step 1 Add 100 cm3 HCl (aq) to a conical flask and weigh. Step 2 Add X2CO3 to the conical flask and immediately reweigh. Step 3 After 5 minutes, reweigh the conical flask and contents. Results Mass of conical flask + HCl (aq) 172.93 g Mass of conical flask + X2CO3 + HCl (aq) before reaction 187.50 g Mass of conical flask + contents after 5 minutes 184.75 g (i) Calculate the amount, in mol, of CO2 released in the reaction. Amount of CO2 = ................................................... mol [1]
181. November 2020 · Paper 3 · Q4(b)(ii) · 3 marks · AO1, 2, 3
(ii) Calculate the molar mass of X2CO3 and identify metal X. Molar mass of X2CO3 = .................... g mol−1 Metal X = ....................[3]
182. November 2020 · Paper 3 · Q4(c)(i) · 1 marks · AO3
(c) After analysing the results, the student was told that their molar mass of X2CO3 was incorrect. The student evaluated the experiment for possible reasons for the incorrect result. (i) The student wondered whether the reaction was complete when the mass was recorded after 5 minutes (Step 3). How could the student modify the experimental procedure to be confident that the reaction was complete? ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1]
183. November 2020 · Paper 3 · Q4(c)(ii) · 2 marks · AO3
(ii) The student finds out that carbon dioxide is slightly soluble in water. State and explain how the solubility of CO2 would affect the calculated molar mass of X2CO3. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2]
184. June 2019 · Paper 1 · Q3 · 1 marks · AO2
3 One molecule of a gas has a mass of 2.658 × 10−23 g. What is a possible formula of the gas? A CH4 B O2 C SO2 D SO3 Your answer [1]
185. June 2019 · AS Paper 1 · Q4 · 1 marks · AO1
4 Which chemical process is the most sustainable in terms of the atom economy of the organic product? A CO2 + 3H2 → CH3OH + H2O B CH3CH2OH + NaCl + H2SO4 → CH3CH2Cl + NaHSO4 + H2O C CH3CH2Br + NaOH → CH3CH2OH + NaBr D CH3CH2CH2CH2OH → CH3CH2CH=CH2 + H2O Your answer [1]
186. June 2019 · Paper 1 · Q4 · 1 marks · AO2
4 In the laboratory, acid spills can be cleaned up and made safe by spreading anhydrous sodium carbonate over the spill to neutralise the acid. A student accidentally spills 50.0 cm3 of 2.00 mol dm−3 HCl (aq) on the bench. What is the minimum mass of anhydrous sodium carbonate required to neutralise the acid? A 4.15 g B 5.30 g C 8.30 g D 10.6 g Your answer [1]
187. June 2019 · AS Paper 1 · Q5 · 1 marks · AO2
5 8.0 dm3 of NO is mixed with 6.0 dm3 of O2 at room temperature and pressure (RTP). The reaction below takes place until one of the reactants is used up. 2NO(g) + O2(g) → 2NO2(g) What is the volume of the mixture at RTP after the reaction has taken place? A 8.0 dm3 B 10.0 dm3 C 12.0 dm3 D 14.0 dm3 Your answer [1]
188. June 2019 · AS Paper 1 · Q6 · 1 marks · AO2
6 What is the volume of 0.0100 mol of N2 at 350 °C and 200 kPa? A 145 cm3 B 259 cm3 C 145 dm3 D 259 dm3 Your answer [1]
189. June 2019 · AS Paper 1 · Q7 · 1 marks · AO2
7 0.24 g of an element, X, is reacted with 0.0100 mol Cl 2 to form a chloride with the formula XCl 2. What is element X? A carbon B magnesium C molybdenum D titanium Your answer [1]
190. June 2019 · Paper 1 · Q8 · 1 marks · AO2
8 3.528 g of a Group 2 metal, M, is reacted with an excess of chlorine. The reaction forms 9.775 g of a chloride. What is metal M? A magnesium B calcium C strontium D barium Your answer [1]
191. June 2019 · Paper 1 · Q10 · 1 marks · AO2
10 Radical reactions are responsible for the catalysed breakdown of the ozone layer. The overall equation is shown below. 2O3 3O2      ∆rH = −284 kJ mol−1 The molar gas volume in the ozone layer is approximately 2.5 m3 mol−1. What is the energy released, in kJ, during the breakdown of 1.0 m3 of ozone in the ozone layer? A 56.8 B 113.6 C 355 D 710 Your answer [1]
192. June 2019 · Paper 1 · Q18(c)(ii) · 5 marks · AO2
(ii) Use the student’s results to determine the mass, in mg, of iron(II) gluconate in one tablet. Give your answer to 3 significant figures. mass of iron(II) gluconate in one tablet = .................................................... mg [5]
193. June 2019 · Paper 1 · Q18(c)(iii) · 1 marks · AO3
(iii) Some iron supplements contain iron(II) sulfate or iron(II) fumarate. The information in Table 18.3 is taken from the labels of two iron supplements, A and B. Mass of iron compound in Iron supplement Iron compound one tablet / mg A iron(II) sulfate, FeSO4 180 B iron(II) fumarate, C4H2FeO4 210 Table 18.3 Choose which iron supplement, A or B, would provide the greater mass of iron per tablet. iron supplement: ......................................................... [1]
194. June 2019 · Paper 1 · Q19(b)(ii) · 5 marks · AO2
(ii) Determine the value of Kp for Equilibrium 1 at 1000 K. Show all your working. Give your answer to 3 significant figures. Kp = ......................................................... [5]
195. June 2019 · Paper 1 · Q20(b)(i) · 1 marks · AO2
(b) A student adds a total of 45.0 cm3 of 0.100 mol dm−3 NaOH(aq) to 25.0 cm3 of 0.0800 mol dm−3 C2H5COOH(aq) and monitors the pH throughout. (i) Show by calculation that 20.0 cm3 of NaOH(aq) is required to reach the end point. [1]
196. June 2019 · Paper 1 · Q20(b)(ii) · 4 marks · AO1, 2
(ii) Calculate the pH of the final solution. Give your answer to 2 decimal places. pH = ......................................................... [4]
197. June 2019 · AS Paper 1 · Q22(b) · 3 marks · AO2
(b) Calculate the concentration, in mol dm−3, of the hydrochloric acid. Give your answer to 3 significant figures. concentration of HCl = .......................................... mol dm−3 [3]
198. June 2019 · AS Paper 1 · Q25(b)(iii) · 3 marks · AO3
(iii) Organic compound E is formed by the substitution of some of the H atoms in butane by Cl atoms. A chemist found that 0.636 g of compound E has a volume of 78.0 cm3. Under the conditions used, the molar gas volume is 32.5 dm3 mol−1. Determine the molecular formula of compound E. molecular formula = ......................................................... [3]
199. June 2019 · AS Paper 2 · Q1(d)(i) · 3 marks · AO3
(d) When hydrated strontium chloride is heated, the water of crystallisation is removed, leaving a residue of anhydrous strontium chloride. A student carries out an experiment to find the value of x in the formula of hydrated strontium chloride, SrCl2•xH2O. The student’s method is outlined below. Step 1 Weigh an empty crucible. Add SrCl2•xH2O to the crucible and reweigh. Step 2 Heat the crucible and contents for 10 minutes. Allow to cool and reweigh. Step 3 Heat the crucible and residue for another 5 minutes. Allow to cool and weigh the crucible and residue. Repeat step 3 a further two times. The student’s results are shown below: Mass of empty crucible / g 15.96 Mass of crucible + SrCl2•xH2O / g 18.65 First mass of crucible + residue / g 17.66 Second mass of crucible + residue / g 17.61 Third mass of crucible + residue / g 17.58 Fourth mass of crucible + residue / g 17.58 (i) Calculate the value of x in SrCl2•xH2O. Give your answer to 2 significant figures. x = .......................................................... [3]
200. June 2019 · AS Paper 2 · Q1(d)(ii) · 1 marks · AO3
(ii) Suggest why the student takes four readings of the mass of the crucible and residue. ........................................................................................................................................... ...................................................................................................................................... [1]
201. June 2019 · AS Paper 2 · Q2(a) · 6 marks · AO2
2 Magnesium nitrate is used in fertilisers as a source of nitrogen. (a)* A student plans to prepare 250.0 cm3 of a 0.4000 mol dm–3 solution of magnesium nitrate, starting from magnesium nitrate crystals, Mg(NO3)2•6H2O. Describe how the student would prepare the solution, giving full details of quantities, apparatus and method. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
202. June 2019 · AS Paper 2 · Q2(b) · 3 marks · AO2
(b) A solution of magnesium nitrate can be prepared by reacting magnesium carbonate, MgCO3, with nitric acid, HNO3(aq). The equation is shown below. MgCO3(s) + 2HNO3(aq) Mg(NO3)2(aq) + H2O(l) + CO2(g) Calculate the minimum volume, in cm3, of 1.75 mol dm–3 HNO3 that is needed to prepare a solution containing 5.00 g of Mg(NO3)2. Give your answer to 3 significant figures. volume = ................................................... cm3 [3]
203. June 2019 · AS Paper 2 · Q4(a) · 3 marks · AO2
4 Zinc reacts with hydrochloric acid, HCl(aq), as shown in the following equation. Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g) A student investigates the rate of this reaction. (a) The student plans to react 50.0 cm3 of 0.100 mol dm–3 HCl with 0.200 g of zinc (an excess). Calculate the volume, in cm3, of hydrogen that should be produced at RTP. volume = ................................................... cm3 [3]
204. June 2019 · AS Paper 2 · Q4(c) · 2 marks · AO2
80 70 60 50 volume 40 / cm3 30 20 10 0 Fig. 4.1 (c) The student repeats the experiment using: • zinc with the same mass (0.200 g) and same surface area • the same temperature and pressure • 40.0 cm3 of 0.125 mol dm–3 HCl, instead of 50.0 cm3 of 0.100 mol dm–3 HCl. On your graph in Fig. 4.1 sketch the curve you would expect in this experiment. [2]
205. June 2019 · AS Paper 2 · Q5(b)(i) · 6 marks · AO2, 3
(b) Hex-1-ene is a liquid with a boiling point of 63 °C and a density of 0.67 g cm–3. Hex-1-ene can be prepared by refluxing hexan-1-ol (boiling point 157 °C) with an acid catalyst. Hexan-1-ol is a liquid with a boiling point of 157 °C and a density of 0.82 g cm–3. The equation is shown below. + H2O OH After reflux, the resulting mixture contains unreacted hexan-1-ol, hex-1-ene and water. The mixture is then purified. The expected percentage yield of hex-1-ene from hexan-1-ol is 62.5%. (i)* A student plans to prepare 4.20 g of hex-1-ene by this method. Calculate the mass of hexan-1-ol that the student should use and explain how you could obtain pure hex-1-ene from the mixture obtained after reflux. [6] ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... Additional answer space if required ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...........................................................................................................................................
206. June 2019 · Paper 2 · Q11 · 1 marks · AO2
11 A student reacts 4.50 g of C6H5NH2 with excess CH3COCl in the reaction below. C6H5NH2 + CH3COCl → C6H5NHCOCH3 + HCl Mr = 93.0 Mr = 135.0 The reaction produces 3.25 g of C6H5NHCOCH3. What is the percentage yield of C6H5NHCOCH3? A 49.8 B 68.9 C 72.2 D 95.4 Your answer [1]
207. June 2019 · Paper 2 · Q16(b)(ii) · 1 marks · AO1
(ii) What is the molecular formula of geraniol? ...................................................................................................................................... [1]
208. June 2019 · Paper 2 · Q17(a)(ii) · 4 marks · AO2, 3
(ii) A student is provided with one of the four amino acids in Table 17.1. A student carries out a titration with a standard solution of hydrochloric acid to identify the amino acid. The student’s method is outlined below. • The student dissolves 5.766 g of the amino acid in water and makes the solution up to 250.0 cm3 in a volumetric flask. • The student titrates this solution with 25.0 cm3 of 0.150 mol dm−3 hydrochloric acid. • 21.30 cm3 of the amino acid solution were required for complete neutralisation of the hydrochloric acid. Determine which amino acid the student used. [4]
209. June 2019 · Paper 2 · Q18(e)(i) · 6 marks · AO3
(e)* A student intends to synthesise ester C. H O H3C C C O CH3 CH3 Ester C (i) Plan a two-stage synthesis to prepare 12.75 g of ester C starting from 2-methylpropanal, (CH3)2CHCHO. Assume the overall percentage yield of ester C from 2-methylpropanal is 40%. In your answer include the mass of 2-methylpropanal required, reagents, conditions and equations where appropriate. Purification details are not required. [6] ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... Additional answer space if required ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...........................................................................................................................................
210. June 2019 · Paper 2 · Q21 · 6 marks ·
21* Analysis of an unknown organic compound produced the following results. Elemental analysis by mass C: 73.17%; H: 7.32%; O: 19.51% Mass spectrum Molecular ion peak at m / z = 164.0 Infrared spectrum 100 Transmittance (%) 50 0 4000 3000 2000 1500 1000 500 Wavenumber / cm–1 1H NMR spectrum in D2O 3 4 3 1 8 7 6 5 4 3 2 1 0 Chemical shift, d / ppm The numbers by the peaks are the relative peak areas. Use the results to suggest one possible structure for the unknown compound. Show all your reasoning. [6] .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Additional answer space if required .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..........................................................................................................................................................
211. June 2019 · Paper 3 · Q1(d) · 2 marks · AO2
(d) What mass of carbon dioxide (in g) is formed by the complete combustion of 42.0 m3 (measured at RTP) of propane? mass = ...................................................... g [2]
212. June 2019 · Paper 3 · Q1(f) · 2 marks · AO2
(f) What is the number of oxygen atoms in 4.26 g of P2O5? number of oxygen atoms = ......................................................... [2]
213. June 2019 · Paper 3 · Q2(d) · 3 marks · AO1, 2
(d) Calculate the percentage yield of benzoic acid. Give your answer to 3 significant figures. percentage yield = ...................................................... % [3]
214. June 2019 · Paper 3 · Q3(a)(iv) · 2 marks · AO2
(iv) The student makes suitable modifications to the method and repeats the experiment to obtain the accurate results shown below. Mass of dish / g 8.364 Mass of dish + lead oxide / g 11.818 Mass of dish + lead at end of experiment / g 11.496 Calculate the empirical formula of the lead oxide. empirical formula = ......................................................... [2]
215. June 2019 · Paper 3 · Q4(a)(iv) · 5 marks · AO1, 2
(iv) A student measures the pH of the contents in a bottle of Dettol® as 5.14. The label on the bottle shows the percentage of chloroxylenol in Dettol® as 4.80% i.e. 100 cm3 of Dettol® contains 4.80 g of chloroxylenol. Assume the following: • Chloroxylenol is the only acidic component in Dettol®. • Chloroxylenol is a weak monobasic acid. • The density of Dettol® is 1.00 g cm−3. Write the equation, using molecular formulae, for the acid dissociation of chloroxylenol. Calculate the acid dissociation constant, Ka, for chloroxylenol. Ka = .......................................... mol dm−3 [5]
216. June 2019 · Paper 3 · Q5(a)(i) · 6 marks · AO3
5 This question is about copper(II) sulfate, CuSO4, and sodium thiosulfate, Na2S2O3. (a) The enthalpy change of reaction, ∆rH, for converting anhydrous copper(II) sulfate to hydrated copper(II) sulfate is difficult to measure directly by experiment. CuSO4(s) + 5H2O(l) → CuSO4•5H2O(s) ∆rH reaction 5.1 The enthalpy changes of solution of anhydrous and hydrated copper(II) sulfate can be measured by experiment. The reactions are shown below. In the equations, ‘aq’ represents an excess of water. CuSO4(s) + aq → Cu2+(aq) + SO4 2−(aq) ∆solH(CuSO4(s)) reaction 5.2 CuSO4•5H2O(s) + aq → Cu2+(aq) + SO4 2−(aq) ∆solH(CuSO4•5H2O(s)) reaction 5.3 Experiment 1 A student carries out an experiment to find ∆solH(CuSO4(s)) for reaction 5.2. Student’s method • Weigh a bottle containing CuSO4(s) and weigh a polystyrene cup. • Add about 50 cm3 of water to the polystyrene cup and measure its temperature. • Add the CuSO4(s), stir the mixture, and measure the final temperature. • Weigh the empty bottle and weigh the polystyrene cup with final solution. Mass readings Mass of bottle + CuSO4(s) / g 28.04 Mass of empty bottle / g 20.06 Mass of polystyrene cup / g 23.43 Mass of polystyrene cup + final solution / g 74.13 Temperature readings Initial temperature of water / °C 20.5 Temperature of final solution / °C 34.0 Experiment 2 The student carries out a second experiment with CuSO4•5H2O (reaction 5.3). The student uses the same method as in Experiment 1. The student calculates ∆solH(CuSO4•5H2O(s)) as +8.43 kJ mol−1. (i)* Calculate ∆solH(CuSO4(s)) for reaction 5.2 and determine the enthalpy change of reaction 5.1, ∆rH. Assume that the specific heat capacity, c, of the solution is the same as for water. Show your working, including an energy cycle linking the enthalpy changes. [6] ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... Additional answer space if required ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...........................................................................................................................................
217. June 2019 · Paper 3 · Q6(b) · 6 marks · AO1, 3
(b)* Compound C is a hydrated ionic compound with the empirical formula: FeH18N3O18. A student investigates the thermal decomposition of compound C as outlined below. Stage 1 The student gently heats 0.00300 mol of compound C to remove the water of crystallisation. 0.486 g of water is collected, leaving 0.00300 mol of the anhydrous compound D. Stage 2 The student strongly heats 0.00300 mol of compound D, which decomposes to form a solid oxide E (molar mass of 159.6 g mol−1) and 270 cm3 of a gas mixture, measured at RTP, containing gases F and G. Stage 3 The student cools the 270 cm3 gas mixture of F and G. • Gas F is a compound that condenses to form 0.414 g of a liquid. • Gas G remains and has a volume of 54 cm3, measured at RTP. Gas G is tested and it relights a glowing splint. Determine the formulae of C, D, E, F and G. Show all your working and equations for the reactions. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
218. June 2018 · AS Paper 1 · Q2 · 1 marks ·
2 What is the number of oxygen atoms in 88.0 g of CO2? A 3.01 × 1023 B 1.20 × 1024 C 2.41 × 1024 D 4.82 × 1024 Your answer [1]
219. June 2018 · AS Paper 1 · Q3 · 1 marks ·
3 A compound has the composition by mass: H, 5.00%; N, 35.00%; O, 60.00%. Which compound has this composition? A HNO3 B NH4NO3 C HNO2 D NH2OH Your answer [1]
220. June 2018 · Paper 1 · Q3 · 1 marks · AO2
3 What is the number of hydrogen atoms in 0.125 mol of C2H5OH? A 7.525 × 1022 B 4.515 × 1023 C 3.7625 × 1023 D 3.612 × 1024 Your answer [1]
221. June 2018 · AS Paper 1 · Q4 · 1 marks ·
4 Sodium reacts with water as shown below. 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) Which mass of sodium reacts with water to produce 960 cm3 of hydrogen gas at RTP? A 0.46 g B 0.92 g C 1.84 g D 3.68 g Your answer [1]
222. June 2018 · Paper 1 · Q4 · 1 marks · AO2
4 A student titrates a standard solution of barium hydroxide, Ba(OH)2, with nitric acid, HNO3. 25.00 cm3 of 0.0450 mol dm–3 Ba(OH)2 are needed to neutralise 23.35 cm3 of HNO3(aq). What is the concentration, in mol dm–3, of the nitric acid? A 0.0241 B 0.0482 C 0.0900 D 0.0964 Your answer [1]
223. June 2018 · AS Paper 1 · Q17 · 1 marks ·
17 The structure of naphthalene is shown below. What is the molecular formula of naphthalene? A C10H8 B C10H10 C C12H10 D C12H12 Your answer [1]
224. June 2018 · Paper 1 · Q19(b) · 4 marks ·
(b) Many solid drain cleaners are based on sodium hydroxide, NaOH. • A student dissolves 1.26 g of a drain cleaner in water and makes up the solution to 100.0 cm3. • The student measures the pH of this solution as 13.48. Determine the percentage, by mass, of NaOH in the drain cleaner. Give your answer to three significant figures. percentage = ..................................................... % [4]
225. June 2018 · Paper 1 · Q20(c) · 4 marks ·
(c) Compound A is an oxide of chlorine that is a liquid at room temperature and pressure and has a boiling point of 83 °C. When 0.4485 g of A is heated to 100 °C at 1.00 × 105 Pa, 76.0 cm3 of gas is produced. Determine the molecular formula of compound A. Show all your working. molecular formula of A = ......................................................... [4]
226. June 2018 · Paper 1 · Q20(d)(iv) · 5 marks ·
(iv) Determine the relative formula mass and formula of the Group 1 iodate(V), B. Show your working. relative formula mass of B = ............................................................... formula of B = .......................................................... [5]
227. June 2018 · Paper 1 · Q21(d) · 6 marks ·
(d)* Three different reactions of copper compounds are described below. Reaction 1: Aqueous copper(II) sulfate reacts with excess aqueous ammonia in a ligand substitution reaction. A deep-blue solution is formed, containing an octahedral complex ion, C, which is a trans isomer. Reaction 2: Copper(I) oxide reacts with hot dilute sulfuric acid in a disproportionation reaction. A blue solution, D, and a brown solid, E are formed. Reaction 3: Copper(II) oxide reacts with warm dilute nitric acid in a neutralisation reaction, to form a blue solution. Unreacted copper(II) oxide is filtered off, and the solution is left overnight in an evaporating basin. A hydrated salt, F, crystallises, with the percentage composition by mass: Cu, 26.29%; H, 2.48%; N, 11.59%; O, 59.63%. Identify C–F by formulae or structures, as appropriate. Include equations, any changes in oxidation number, and working. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
228. June 2018 · AS Paper 1 · Q22(a)(ii) · 3 marks ·
(ii) The student plans to add magnesium to 50.0 cm3 of 1.24 mol dm−3 H3PO4. Calculate the mass of magnesium that the student should add to react exactly with the phosphoric acid. Give your answer to three significant figures. mass of Mg = ...................................................... g [3]
229. June 2018 · AS Paper 1 · Q22(b)(i) · 4 marks ·
(b) Phosphine, PH3, is a gas formed by heating phosphorous acid, H3PO3, in the absence of air. 4H3PO3(s) → PH3(g) + 3H3PO4(s) (i) 3.20 × 10−2 mol of H3PO3 is completely decomposed by this reaction. Calculate the volume of phosphine gas formed, in cm3, at 100 kPa pressure and 200 °C. volume of PH3 = .................................................. cm3 [4]
230. June 2018 · AS Paper 1 · Q23(a)(i) · 4 marks ·
23 This question is about energy changes and rate of reaction. (a) Magnesium reacts with aqueous silver nitrate, AgNO3(aq), as in equation 23.1. Mg(s) + 2AgNO3(aq) → 2Ag(s) + Mg(NO3)2(aq) Equation 23.1 A student carries out an experiment to determine the enthalpy change of this reaction, ∆rH. • The student adds 25.0 cm3 of 0.512 mol dm−3 AgNO3 to a polystyrene cup. • The student measures the temperature of the solution. • The student adds a small spatula measure of magnesium powder, stirs the mixture and records the maximum temperature. Temperature readings Initial temperature = 19.5 °C Maximum temperature = 47.5 °C (i) Calculate ∆rH, in kJ mol−1, for the reaction shown in equation 23.1. Give your answer to an appropriate number of significant figures. Assume that the density and specific heat capacity, c, of the solution are the same as for water and that all the aqueous silver nitrate has reacted. ∆rH = ........................................... kJ mol−1 [4]
231. June 2018 · AS Paper 2 · Q1(d)(i) · 4 marks ·
(d) A student repeats the titration to determine the molar mass and structure of A. • The student prepares a 250.0 cm3 solution from 1.513 g of A. • The solution of A is added to the burette and titrated with 25.0 cm3 volumes of 0.112 mol dm–3 NaOH(aq). • 1 mol of A reacts with 2 mol of NaOH. • The student obtains a mean titre of 27.30 cm3. (i) Calculate the molar mass of A from these results. Give your answer to the nearest whole number. Show your working. molar mass of A = ............................................. g mol–1 [4]
232. June 2018 · AS Paper 2 · Q4(a)(ii) · 4 marks ·
(ii) 5.10 tonnes of NH3 are converted into NO. Calculate the energy released, in kJ, for this conversion. Give your answer in standard form and to an appropriate number of significant figures. energy released = ..................................................... kJ [4]
233. June 2018 · AS Paper 2 · Q5(a)(ii) · 2 marks ·
(ii) The student used 0.150 mol of butan-1-ol. The student obtained a 61.4% percentage yield of 1-bromobutane. Calculate the mass of 1-bromobutane obtained. Give your answer to three significant figures. mass = ...................................................... g [2]
234. June 2018 · Paper 2 · Q7 · 1 marks ·
7 Ethanol can be prepared by different reactions. Which reaction has the lowest atom economy? A C6H12O6 → 2C2H5OH + 2CO2 B C2H4 + H2O → C2H5OH C C2H5Br + H2O → C2H5OH + HBr D CH3COOC2H5 + H2O → C2H5OH + CH3COOH Your answer [1]
235. June 2018 · Paper 2 · Q19(c)(ii) · 3 marks ·
(ii) Analyse the information to identify E, F and G. Show your working. [3]
236. June 2018 · Paper 2 · Q21(c)(i) · 2 marks ·
(c) A cosmetic product containing four esters, J, K, L and M, is analysed by gas chromatography and mass spectrometry. The results are shown below. Gas chromatogram M 5.9 K J 4.3 4.2 L 1.0 0 1 2 3 4 5 retention time / minutes The numbers by the peaks are the relative molar proportions of the compounds in the mixture. Mass spectrometry ester m/z of molecular ion peak J 152 K 166 L 180 M 180 (i) The concentration of ester K in the cosmetic product is 9.13 × 10−2 g dm−3. Using the results, calculate the concentration, in mol dm−3, of ester M in the cosmetic product. Give your answer to two significant figures. concentration of ester M = .......................................... mol dm−3 [2]
237. June 2018 · Paper 2 · Q22(c)(i) · 5 marks ·
(c) Fuel additives are often used to improve the combustion of a fuel. (i) Compound N is a fuel additive containing carbon, hydrogen and oxygen only. Complete combustion of 1.71 g of compound N produces 2.97 g of CO2 and 1.62 g of H2O. The relative molecular mass of compound N is 76.0. Calculate the molecular formula of N and suggest a possible structure for the compound. compound N [5]
238. June 2018 · Paper 2 · Q22(d) · 6 marks ·
(d)* A scientist is researching compounds that might be suitable as fuel additives. One of the compounds gives the analytical results below. Elemental analysis by mass: C: 54.54%; H: 9.10%; O: 36.36% Mass spectrum: Molecular ion peak at m/z = 132.0 1H NMR spectrum in D2O 6 3 1 5 4 3 2 1 0 chemical shift,  / ppm The numbers by the peaks are the relative peak areas. When the spectrum is run without D2O, there are two additional peaks with the same relative peak areas at 11.0 ppm and 3.6 ppm. Use the information provided to suggest a structure for the compound. Show all your reasoning. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
239. June 2018 · Paper 3 · Q1(a)(viii) · 1 marks ·
(viii) The element which has a density of 1.33 × 10–3 g cm–3 at room temperature and pressure. .............................. [1]
240. June 2018 · Paper 3 · Q2(a)(ii) · 3 marks ·
(ii) The student allows the reaction in equation 2.1 to proceed until no more gas is evolved. The volume of O2 in the syringe is now 55 cm3, measured at RTP. Calculate the initial concentration of the H2O2. Give your answer to two significant figures. initial concentration of H2O2 = ........................................... mol dm–3 [3]
241. June 2018 · Paper 3 · Q3(b)(ii) · 6 marks ·
(ii) Calculate the percentage, by mass, of ethanedioic acid in the rhubarb leaves. Give your answer to an appropriate number of significant figures. percentage of ethanedioic acid = ...................................................... % [6]
242. June 2018 · Paper 3 · Q4(b)(ii) · 6 marks ·
(ii)* A chemist prepares a pure solid sample of paracetamol from 4-nitrophenol in two stages: H Stage 1 Stage 2 HO NO2 Intermediate HO N CH3COCl C CH3 4-nitrophenol paracetamol O Describe a two-stage synthesis of 5.00 g of pure paracetamol from 4-nitrophenol. The overall percentage yield of paracetamol from 4-nitrophenol is 40.0%. In your answer, include the mass of 4-nitrophenol required, the reagents and intermediate, and details of the purification of paracetamol. [6] ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... Additional answer space if required. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...........................................................................................................................................
243. June 2018 · Paper 3 · Q5(a) · 4 marks ·
5 A student carries out two experiments in the laboratory based on succinic acid (butanedioic acid), (CH2COOH)2. (a) Aqueous succinic acid can be neutralised by aqueous sodium hydroxide, NaOH(aq): (CH2COOH)2(aq) + 2NaOH(aq) → (CH2COONa)2(aq) + 2H2O(l) This reaction can be used to determine a value for the enthalpy change of neutralisation, ∆neutH. The student follows this method: • Add 50.0 cm3 of 0.400 mol dm–3 succinic acid to a polystyrene cup. • Measure out 50.0 cm3 of 1.00 mol dm–3 NaOH(aq), which is in excess. • Measure the temperature of both solutions. • Add the NaOH(aq) to the aqueous succinic acid in the polystyrene cup, stir the mixture, and record the maximum temperature. Temperature readings Maximum temperature of mixture/°C 26.5 Initial temperature of both solutions/°C 21.5 Calculate a value for the enthalpy change of neutralisation, ∆neutH, in kJ mol–1. Assume that the density of all solutions and the specific heat capacity, c, of the reaction mixture are the same as for water. ΔneutH = ............................................ kJ mol–1 [4]
244. June 2017 · AS Paper 1 · Q2 · 1 marks ·
2 An organic compound has the composition by mass: C, 53.33 %; H, 11.11%; O, 35.56%. What is the empirical formula of the organic compound? A C4H8O2 B C4H10O2 C C2H4O D C2H5O Your answer [1]
245. June 2017 · AS Paper 1 · Q3 · 1 marks ·
3 Samples of four hydrocarbons are completely burnt under the same conditions of temperature and pressure. Which sample produces the greatest volume of CO2? A 0.4 mol C2H6 B 0.3 mol C3H8 C 0.2 mol C4H10 D 0.1 mol C5H12 Your answer [1]
246. June 2017 · AS Paper 1 · Q4 · 1 marks ·
4 Which reaction produces the smallest atom economy of BaCl2? A BaCl2•2H2O → BaCl2 + 2H2O B BaO + 2HCl → BaCl2 + H2O C BaCO3 + 2HCl → BaCl 2 + CO2 + H2O D Ba + 2HCl → BaCl 2 + H2 Your answer [1]
247. June 2017 · Paper 1 · Q5 · 1 marks ·
5 0.0200 mol of calcium oxide is reacted completely with 2.00 mol dm–3 HCl. What is the volume, in cm3, of 2.00 mol dm–3 HCl required for this reaction? A 15 B 20 C 30 D 60 Your answer [1]
248. June 2017 · Paper 1 · Q6 · 1 marks ·
6 How many electrons are removed from 2.02 × 10–2 g of Ne(g) atoms to form Ne+(g) ions? A 3.36 × 10–26 B 1.66 × 10–27 C 6.02 × 1020 D 1.22 × 1022 Your answer [1]
249. June 2017 · Paper 1 · Q7 · 1 marks ·
7 Silicon can be made by heating silicon tetrachloride, SiCl 4, with zinc. SiCl 4 + 2Zn Si + 2ZnCl 2 8.50 g of SiCl 4 is reacted with an excess of zinc. The percentage yield of silicon is 90%. What is the mass of silicon made? A 1.26 g B 1.31 g C 1.40 g D 1.55 g Your answer [1]
250. June 2017 · Paper 1 · Q12 · 1 marks ·
12 HA and HB are two strong monobasic acids. 25.0 cm3 of 6.0 mol dm–3 HA is mixed with 45.0 cm3 of 3.0 mol dm–3 HB. What is the H+(aq) concentration, in mol dm–3, in the resulting solution? A 1.9 B 2.1 C 4.1 D 4.5 Your answer [1]
251. June 2017 · AS Paper 1 · Q15 · 1 marks ·
15 The skeletal formula of an organic compound is shown below. O OH What is the molecular formula of the organic compound? A C6H10O2 B C6H11O2 C C6H12O2 D C6H13O2 Your answer [1]
252. June 2017 · Paper 1 · Q19(a) · 3 marks ·
19 Aqueous solutions of hydrogen peroxide, H2O2(aq), decompose as in the equation below. 2H2O2(aq) 2H2O(l) + O2(g) A student investigates the decomposition of H2O2(aq) by measuring the volume of oxygen gas produced over time. All gas volumes are measured at room temperature and pressure. The student uses 25.0 cm3 of 2.30 mol dm–3 H2O2. From the results, the student determines the concentration of H2O2(aq) at each time. The student then plots a concentration–time graph. 2.5 2.0 1.5 [H2O2(aq)] / mol dm–3 1.0 0.5 0.0 0 500 1000 1500 2000 2500 3000 time / s (a) Determine the total volume of oxygen, measured at room temperature and pressure, that the student should be prepared to collect in this investigation. Suggest apparatus that would allow this gas volume to be collected, indicating clearly the scale of working. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [3]
253. June 2017 · Paper 1 · Q21(c)(i) · 5 marks ·
(c) The student plans to prepare a buffer solution that has a pH of 4.50. The buffer solution will contain ethanoic acid, CH3COOH, and sodium ethanoate, CH3COONa. The student plans to add 9.08 g CH3COONa to 250 cm3 of 0.800 mol dm–3 CH3COOH. The student assumes that the volume of the solution does not change. (i) Show by calculation whether, or not, the student’s experimental method would produce the required pH. Show all your working. [5]
254. June 2017 · AS Paper 1 · Q22(c)(ii) · 1 marks ·
(ii) Estimate the energy required to form one Na+(g) ion from one Na(g) atom. Give your answer in kJ, in standard form, and to two significant figures. energy = ..................................................... kJ [1]
255. June 2017 · Paper 1 · Q23(b) · 6 marks ·
(b)* A hydrated nickel(II) complex, A, is heated in a crucible to remove the water of crystallisation. The anhydrous complex B is formed. The results are shown below. Mass of crucible + hydrated complex A = 59.554 g Mass of crucible + anhydrous complex B = 58.690 g Mass of crucible = 51.257 g The anhydrous complex B is analysed and found to have a molar mass of 309.7 g mol–1 and to contain the following percentage composition by mass: Ni, 18.95%; C, 23.25%; N, 27.12%; H, 7.75%; Cl, 22.93%. The anhydrous complex B contains a cation C comprising Ni, C, N and H only. Cation C is six-coordinate, contains three molecules of the bidentate ligand D, and exists as optical isomers. Determine the formula of A, B, C and D and show the 3D structures for the optical isomers of C. Show all your working. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [6]
256. June 2017 · AS Paper 1 · Q24(c)(i) · 4 marks ·
(c) A student plans to determine the concentration, in mol dm–3, of CH3COOH in a bottle of vinegar. The student will carry out a titration with aqueous barium hydroxide, Ba(OH)2(aq). The student’s method is outlined below. • Dilute 10.0 cm3 of vinegar from the bottle with distilled water and make the solution up to 250.0 cm3. • Add the diluted vinegar to the burette. • Titrate 25.0 cm3 volumes of 0.0450 mol dm–3 Ba(OH)2 with the diluted vinegar. The mean titre of the diluted vinegar is 25.45 cm3. The reaction in the student’s titration is shown below. 2CH3COOH(aq) + Ba(OH)2(aq) → (CH3COO)2Ba(aq) + 2H2O(l) (i) Calculate the concentration, in mol dm–3, of CH3COOH in the original bottle of vinegar. Show your working. concentration of CH3COOH = .......................................... mol dm–3 [4]
257. June 2017 · AS Paper 1 · Q25(b) · 5 marks ·
(b) An alkene D is a liquid at room temperature and pressure but can easily be vaporised. When vaporised, 0.1881 g of D produces 82.5 cm3 of gas at 101 kPa and 373 K. Determine the molar mass and molecular formula of alkene D. Show all your working. molar mass = .................................................. g mol−1 molecular formula = .......................................................... [5]
258. June 2017 · AS Paper 2 · Q1(a)(iii) · 2 marks ·
(iii) Calculate the number of barium ions in 1.50 g of barium oxide. Give your answer in standard form and to three significant figures. number of barium ions = .......................................................... [2]
259. June 2017 · AS Paper 2 · Q1(b)(iii) · 2 marks ·
(iii) Hydrated barium chloride can be crystallised from solution. Hydrated barium chloride has the formula BaCl2•xH2O and a molar mass of 244.3 g mol −1. Determine the value of x in the formula of BaCl2•xH2O. Show your working. x = .......................................................... [2]
260. June 2017 · AS Paper 2 · Q2 · 6 marks ·
2* A student was asked to carry out an experiment to determine the initial rate of reaction of zinc and hydrochloric acid. The student plans to collect a total of about 72 cm3 of hydrogen at RTP and to use an excess of zinc. The student selects the following apparatus: • the apparatus shown in the diagram • 100 cm3 measuring cylinder • stop clock • 2 decimal place balance 100 cm3 gas syringe Outline how the student could carry out the experiment and explain how the results could be processed graphically. Show all working in your calculations. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [6]
261. June 2017 · Paper 2 · Q3 · 1 marks ·
3 Complete combustion of an organic compound forms 40 cm3 of carbon dioxide and 40 cm3 of water vapour, under the same conditions of temperature and pressure. Which molecular formula could the organic compound have? A C3H8 B C2H2O C C2H4O D C2H3N Your answer [1]
262. June 2017 · AS Paper 2 · Q3(a)(i) · 4 marks ·
3 Alkanes are saturated hydrocarbons with the general formula CnH2n+2. (a) A student carries out an experiment to measure the enthalpy change of combustion, ∆cH, of hexane. The student finds that combustion of 1.29 g of hexane changes the temperature of 200 g of water from 20.5 °C to 65.5 °C. (i) Calculate the enthalpy change of combustion, ∆cH, of hexane, in kJ mol−1. Give your final answer to an appropriate number of significant figures. ∆cH ............................................ kJ mol−1 [4]
263. June 2017 · AS Paper 2 · Q3(b)(ii) · 3 marks ·
(ii) Use the graph to estimate the energy released during complete combustion of 1.80 g of pentane. Show relevant working below and on the graph. energy released = .................................................... kJ [3]
264. June 2017 · Paper 2 · Q5 · 1 marks ·
5 Which type of reaction has the greatest atom economy? A Substitution B Hydrolysis C Elimination D Addition Your answer [1]
265. June 2017 · AS Paper 2 · Q6(a)(ii) · 3 marks ·
(ii) The student carries out this synthesis and obtains 1.23 g of pure cyclohexene from 5.50 g of bromocyclohexane. Calculate the percentage yield of cyclohexene. Give your final answer to an appropriate number of significant figures. percentage yield = ..................................................... % [3]
266. June 2017 · Paper 2 · Q9 · 1 marks ·
9 What is the molecular formula of the compound below? A C7H10 B C7H12 C C7H14 D C7H16 Your answer [1]
267. June 2017 · Paper 2 · Q12 · 1 marks ·
12 0.1 mol of HOOCCH2COOH are reacted with 0.1 mol of aqueous NaOH. How many molecules of water are formed? A 6.02 × 1022 B 3.01 × 1022 C 6.02 × 1023 D 3.01 × 1023 Your answer [1]
268. June 2017 · Paper 2 · Q16(e)(i) · 2 marks ·
(e) Myrcene, C10H16, is a naturally occurring hydrocarbon containing more than one carbon-carbon double bond. myrcene (i) Reaction of 204 mg of myrcene with hydrogen gas produces a saturated alkane. Calculate the volume of hydrogen gas, in cm3 and measured at RTP, needed for this reaction. Show your working. volume = .................................................. cm3 [2]
269. June 2017 · Paper 2 · Q16(e)(ii) · 4 marks ·
(ii) β-Carotene is a naturally occurring unsaturated hydrocarbon found in carrots. A β-carotene molecule contains 40 carbon atoms, has two rings, and a branched chain. 0.0200 mol of β-carotene reacts with 5.28 dm3 of hydrogen gas to form a saturated hydrocarbon. Using molecular formulae, construct a balanced equation for this reaction. Include relevant calculations and reasoning. Equation ...................................................................................................................... [4]
270. June 2017 · Paper 2 · Q17(a)(ii) · 6 marks ·
(ii)* A chemist carries out the reaction in Equation 17.1 using 4.97 g of benzoic acid. The chemist obtains 3-nitrobenzoic acid as an impure solid. The chemist purifies the solid to obtain 4.85 g of 3-nitrobenzoic acid. Describe a method to obtain a pure sample of 3-nitrobenzoic acid from the impure solid, determine the percentage yield and check its purity. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [6]
271. June 2017 · Paper 2 · Q20(a) · 3 marks · AO1
20 A chemist analyses a naturally occurring aromatic compound. (a) The percentage composition and mass spectrum of the compound are shown below. Percentage composition by mass: C, 70.58%; H, 5.92%; O, 23.50%. Mass spectrum 100 80 60 relative intensity 40 20 0 25 50 75 100 125 150 m /z Determine the molecular formula of the compound. Show your working. molecular formula = ......................................................... [3]
272. June 2017 · Paper 3 · Q1(c) · 2 marks ·
(c) Determine the formula of ‘methane hydrate’, CH4•xH2O. In the formula, show the value of x to two decimal places. formula = ......................................................... [2]
273. June 2017 · Paper 3 · Q1(d) · 4 marks ·
(d) Calculate the volume of methane, in dm3, that would be released from the melting of each 1.00 kg of ‘methane hydrate’ at 101 kPa and 0 °C. Give your answer to three significant figures. volume = ................................................. dm3 [4]
274. June 2017 · Paper 3 · Q2(a) · 6 marks ·
2 A student plans to determine the enthalpy change of reaction 3.1 shown below. Na2O(s) + 2HCl(aq) 2NaCl(aq) + H2O(l) reaction 3.1 This enthalpy change can be determined indirectly using Hess’ Law from the enthalpy changes of reaction 3.2 and reaction 3.3 shown below. Na2O(s) + H2O(l) 2NaOH(aq) reaction 3.2 HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l) ∆rH = −57.6 kJ mol−1 reaction 3.3 The student will determine the enthalpy change of reaction 3.2 as outlined below. • Weigh a bottle containing Na2O(s) and weigh a polystyrene cup. • Add about 25 cm3 of water to the polystyrene cup and measure its temperature. • Add the Na2O(s), stir the mixture, and measure the maximum temperature reached. • Weigh the empty bottle and weigh the polystyrene cup with the final solution. Mass readings Mass of bottle + Na2O(s) = 16.58 g Mass of empty bottle = 15.34 g Mass of empty polystyrene cup = 21.58 g Mass of polystyrene cup + final solution = 47.33 g Temperature readings Initial temperature of water = 20.5 °C Maximum temperature of final solution = 55.5 °C The density and specific heat capacity, c, of the solution are the same as for water. (a)* Calculate the enthalpy change of reaction 3.2 and the enthalpy change of reaction 3.1. Show all your working. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [6]
275. June 2017 · Paper 3 · Q3(c)(ii) · 3 marks ·
(ii) Peroxyethanoic acid can be prepared by reacting hydrogen peroxide with ethanoic acid. This is a heterogeneous equilibrium. H2O2(aq) + CH3COOH(aq) CH3COOOH(aq) + H2O(l) Kc = 0.37 dm3 mol−1 A 250 cm3 equilibrium mixture contains concentrations of 0.500 mol dm−3 H2O2(aq) and 0.500 mol dm−3 CH3COOH(aq). Calculate the amount, in mol, of peroxyethanoic acid in the equilibrium mixture. amount = .................................................. mol [3]
276. June 2017 · Paper 3 · Q4(a)(ii) · 6 marks ·
(ii) The structure of compound A is shown below. O HO OH R compound A Compound A has four optical isomers. Using this information and the student’s results, answer the following. • Determine the molar mass of A and the formula of the alkyl group R. • Draw the structure of compound A and label any chiral carbon atoms with an asterisk*. Show all your working. [6]
277. June 2017 · Paper 3 · Q4(c)(ii) · 2 marks ·
(ii) A typical tablet of chromium(III) picolinate contains 200 μg of chromium. Calculate the mass, in g, of chromium(III) picolinate in a typical tablet. 1 μg = 10−6 g. Give your answer to three significant figures. mass = ...................................................... g [2]
278. June 2016 · AS Paper 1 · Q3 · 1 marks ·
3 Calcium nitrate, Ca(NO3)2, decomposes when heated, as shown below. Ca(NO3)2(s) → CaO(s) + 2NO2(g) + ½O2(g) A student decomposes 0.00500 mol of Ca(NO3)2 and collects the gas that is produced. Calculate the volume of gas that the student should expect to collect, measured at room temperature and pressure. A 60 cm3 B 120 cm3 C 240 cm3 D 300 cm3 Your answer [1]
279. June 2016 · AS Paper 1 · Q21(b)(ii) · 2 marks · AO2
13 (ii) One coin has a mass of 5.00 g and contains 84.0% of copper, by mass. Calculate the number of copper atoms in one coin. Give your answer in standard form and to three significant figures. number of copper atoms = .......................................................... [2]
280. June 2016 · AS Paper 1 · Q22(a) · 3 marks · AO1, 2
14 22 This question is about several salts. (a) A hydrated salt, compound A, is analysed and has the following percentage composition by mass: Cr, 19.51%; Cl, 39.96%; H, 4.51%; O, 36.02%. Calculate the formula of compound A, showing clearly the water of crystallisation. Show your working. formula of compound A = .......................................................... [3]
281. June 2016 · AS Paper 1 · Q22(b)(iii) · 1 marks · AO3
(iii) The student is not sure that all the water of crystallisation has been removed. How could the student modify the experiment to be confident that all the water of crystallisation has been removed? ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1]
282. June 2016 · AS Paper 1 · Q22(c) · 3 marks · AO2
16 (c) A student prepares a solution of sodium sulfate, Na2SO4, by adding 6.25 × 10–2 mol dm–3 sulfuric acid, H2SO4, from a burette to 25.0 cm3 of 0.124 mol dm–3 NaOH in a conical flask. 2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + 2H2O(l) Calculate the minimum volume of the H2SO4 that the student would need to completely react with the NaOH present. volume of H2SO4 = .................................................. cm3 [3]
283. June 2016 · AS Paper 1 · Q24(a) · 4 marks · AO2
18 24 Aqueous lead(II) nitrate, Pb(NO3)2(aq), and aqueous potassium iodide, KI(aq), react together. The equation is shown below. Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) A student carries out an experiment to determine the enthalpy change of reaction, ΔrH, of this reaction. The student follows the method outlined below. • Add 50.0 cm3 of 1.50 mol dm–3 Pb(NO3)2(aq) to a polystyrene cup. • Measure out 50.0 cm3 of a solution of KI(aq), which is in excess. • Measure the temperature of both solutions. • Add the KI(aq) to the polystyrene cup, stir the mixture and record the maximum temperature. Temperature readings Initial temperature of both solutions = 19.5 °C Maximum temperature of mixture = 30.0 °C (a) Calculate ΔrH, in kJ mol–1, for the reaction shown in the equation above. Give your answer to an appropriate number of significant figures. Assume that the density of all solutions and specific heat capacity, c, of the reaction mixture is the same as for water. ΔrH = ............................................ kJ mol–1 [4]
284. June 2016 · AS Paper 1 · Q24(c) · 2 marks · AO2
(c) The 50.0 cm3 of KI(aq) used in the experiment contains 10% more KI than is needed to react with 50.0 cm3 of 1.50 mol dm–3 Pb(NO3)2(aq). Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Calculate the concentration, in mol dm–3, of KI that the student used. concentration of KI = ...........................................mol dm–3 [2]
285. June 2016 · AS Paper 1 · Q26(c)(i) · 1 marks · AO1
23 (c) The structure of compound F is shown below. H CH3 HO C C OH H CH3 Compound F (i) What is the empirical formula of compound F? ...................................................................................................................................... [1]
286. June 2016 · AS Paper 2 · Q1(c)(i) · 2 marks · AO3
3 (c) A student reacts a Group 2 metal, M, with water. M(s) + 2H2O(l) M(OH)2(aq) + H2(g) The student measures the volume of hydrogen gas produced. 0.162 g of the metal produces 97.0 cm3 of gas measured at room temperature and pressure. (i) Draw a labelled diagram of the apparatus that can be used to carry out this experiment. [2]
287. June 2016 · AS Paper 2 · Q1(c)(ii) · 3 marks · AO2, 3
(ii) Identify the Group 2 metal, M. Show your working. Group 2 metal = .......................................................... [3]
288. June 2016 · AS Paper 2 · Q1(d) · 1 marks · AO3
(d) The student plans to repeat the experiment using the same mass of a Group 2 metal from further down the group. Predict whether the volume of hydrogen produced would be greater than, less than or the same as the volume in the first experiment. Explain your answer. ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [1]
289. June 2016 · AS Paper 2 · Q4(b) · 4 marks · AO2
11 (b) N2O is supplied as a compressed gas in steel cylinders for use as an anaesthetic. The cylinders are stored at 20.0 °C. Calculate the gas pressure, in Pa, in a 2.32 dm3 steel cylinder containing 187 g of N2O gas. Give your answer in standard form to three significant figures. pressure = .................................................... Pa [4]
290. June 2016 · AS Paper 2 · Q5(a)(ii) · 3 marks · AO2
(ii) An excess of strontium carbonate, SrCO3, is mixed with 20.0 cm3 of 1.25 mol dm–3 nitric acid, HNO3. Calculate the mass of SrCO3 that reacts with the HNO3. mass = ...................................................... g [3]
291. June 2016 · AS Paper 2 · Q6(d) · 3 marks · AO1, 2
(d) 20.2 g of butan-2-ol is reacted with excess sodium bromide and sulfuric acid. CH3CH(OH)CH2CH3 + NaBr + H2SO4 CH3CHBrCH2CH3 + NaHSO4 + H2O 25.2 g of CH3CHBrCH2CH3 is formed. Calculate the percentage yield of CH3CHBrCH2CH3. percentage yield = ..................................................... % [3]

Mark schemes

1. June 2025 · Paper 1 · Q2
Mark scheme June 2025 Paper 1 Q2
2. June 2025 · AS Paper 1 · Q3
Mark scheme June 2025 Paper 1 Q3
3. June 2025 · AS Paper 1 · Q4
Mark scheme June 2025 Paper 1 Q4
4. June 2025 · Paper 1 · Q4
Mark scheme June 2025 Paper 1 Q4
5. June 2025 · Paper 1 · Q19(c)
Mark scheme June 2025 Paper 1 Q19(c)
6. June 2025 · Paper 1 · Q21(b)(ii)
Mark scheme June 2025 Paper 1 Q21(b)(ii)
7. June 2025 · AS Paper 1 · Q21(d)(i)
Mark scheme June 2025 Paper 1 Q21(d)(i)
8. June 2025 · Paper 1 · Q21(d)(i)
Mark scheme June 2025 Paper 1 Q21(d)(i)
9. June 2025 · AS Paper 1 · Q25(c)
Mark scheme June 2025 Paper 1 Q25(c)
10. June 2025 · AS Paper 2 · Q1(c)(i)
Mark scheme June 2025 Paper 2 Q1(c)(i)
11. June 2025 · Paper 2 · Q2
Mark scheme June 2025 Paper 2 Q2
12. June 2025 · AS Paper 2 · Q2(b)(i)
Mark scheme June 2025 Paper 2 Q2(b)(i)
13. June 2025 · AS Paper 2 · Q2(b)(ii)
Mark scheme June 2025 Paper 2 Q2(b)(ii)
14. June 2025 · AS Paper 2 · Q2(b)(iii)
Mark scheme June 2025 Paper 2 Q2(b)(iii)
15. June 2025 · Paper 2 · Q3
Mark scheme June 2025 Paper 2 Q3
16. June 2025 · AS Paper 2 · Q3(a)(iii)
Mark scheme June 2025 Paper 2 Q3(a)(iii)
17. June 2025 · AS Paper 2 · Q4(b)(ii)
Mark scheme June 2025 Paper 2 Q4(b)(ii)
18. June 2025 · Paper 2 · Q5
Mark scheme June 2025 Paper 2 Q5
19. June 2025 · AS Paper 2 · Q5(c)
Mark scheme June 2025 Paper 2 Q5(c)
20. June 2025 · Paper 2 · Q6
Mark scheme June 2025 Paper 2 Q6
21. June 2025 · Paper 2 · Q16(b)
Mark scheme June 2025 Paper 2 Q16(b)
22. June 2025 · Paper 2 · Q17
Mark scheme June 2025 Paper 2 Q17
23. June 2025 · Paper 3 · Q2(a)(ii)
Mark scheme June 2025 Paper 3 Q2(a)(ii)
24. June 2025 · Paper 3 · Q2(b)(ii)
Mark scheme June 2025 Paper 3 Q2(b)(ii)
25. June 2025 · Paper 3 · Q2(c)
Mark scheme June 2025 Paper 3 Q2(c)
26. June 2025 · Paper 3 · Q4(b)(i)
Mark scheme June 2025 Paper 3 Q4(b)(i)
27. June 2025 · Paper 3 · Q5(a)(ii)
Mark scheme June 2025 Paper 3 Q5(a)(ii)
28. June 2025 · Paper 3 · Q6
Mark scheme June 2025 Paper 3 Q6
29. June 2024 · AS Paper 1 · Q3
Mark scheme June 2024 Paper 1 Q3
30. June 2024 · Paper 1 · Q3
Mark scheme June 2024 Paper 1 Q3
31. June 2024 · AS Paper 1 · Q4
Mark scheme June 2024 Paper 1 Q4
32. June 2024 · Paper 1 · Q7
Mark scheme June 2024 Paper 1 Q7
33. June 2024 · AS Paper 1 · Q8
Mark scheme June 2024 Paper 1 Q8
34. June 2024 · Paper 1 · Q19(b)(i)
Mark scheme June 2024 Paper 1 Q19(b)(i)
35. June 2024 · Paper 1 · Q21(b)
Mark scheme June 2024 Paper 1 Q21(b)
36. June 2024 · AS Paper 1 · Q21(c)
Mark scheme June 2024 Paper 1 Q21(c)
37. June 2024 · AS Paper 1 · Q22(b)(iii)
Mark scheme June 2024 Paper 1 Q22(b)(iii)
38. June 2024 · AS Paper 2 · Q1(d)
Mark scheme June 2024 Paper 2 Q1(d)
39. June 2024 · AS Paper 2 · Q2(b)(ii)
Mark scheme June 2024 Paper 2 Q2(b)(ii)
40. June 2024 · AS Paper 2 · Q3(b)
Mark scheme June 2024 Paper 2 Q3(b)
41. June 2024 · AS Paper 2 · Q4(b)(iii)
Mark scheme June 2024 Paper 2 Q4(b)(iii)
42. June 2024 · Paper 2 · Q6
Mark scheme June 2024 Paper 2 Q6
43. June 2024 · Paper 2 · Q10
Mark scheme June 2024 Paper 2 Q10
44. June 2024 · Paper 2 · Q23(c)
Mark scheme June 2024 Paper 2 Q23(c)
45. June 2024 · Paper 3 · Q1(b)
Mark scheme June 2024 Paper 3 Q1(b)
46. June 2024 · Paper 3 · Q1(d)
Mark scheme June 2024 Paper 3 Q1(d)
47. June 2024 · Paper 3 · Q2(a)(iii)
Mark scheme June 2024 Paper 3 Q2(a)(iii)
48. June 2024 · Paper 3 · Q2(b)(ii)
Mark scheme June 2024 Paper 3 Q2(b)(ii)
49. June 2024 · Paper 3 · Q2(c)(i)
Mark scheme June 2024 Paper 3 Q2(c)(i)
50. June 2024 · Paper 3 · Q3(b)(iv)
Mark scheme June 2024 Paper 3 Q3(b)(iv)
51. June 2023 · Paper 1 · Q1
Mark scheme June 2023 Paper 1 Q1
52. June 2023 · AS Paper 1 · Q2
Mark scheme June 2023 Paper 1 Q2
53. June 2023 · Paper 1 · Q2
Mark scheme June 2023 Paper 1 Q2
54. June 2023 · AS Paper 1 · Q3
Mark scheme June 2023 Paper 1 Q3
55. June 2023 · Paper 1 · Q3
Mark scheme June 2023 Paper 1 Q3
56. June 2023 · Paper 1 · Q4
Mark scheme June 2023 Paper 1 Q4
57. June 2023 · AS Paper 1 · Q7
Mark scheme June 2023 Paper 1 Q7
58. June 2023 · AS Paper 1 · Q8
Mark scheme June 2023 Paper 1 Q8
59. June 2023 · AS Paper 1 · Q9
Mark scheme June 2023 Paper 1 Q9
60. June 2023 · AS Paper 1 · Q10
Mark scheme June 2023 Paper 1 Q10
61. June 2023 · Paper 1 · Q18(a)
Mark scheme June 2023 Paper 1 Q18(a)
62. June 2023 · Paper 1 · Q19(b)
Mark scheme June 2023 Paper 1 Q19(b)
63. June 2023 · Paper 1 · Q20(b)
Mark scheme June 2023 Paper 1 Q20(b)
64. June 2023 · Paper 1 · Q20(c)(ii)
Mark scheme June 2023 Paper 1 Q20(c)(ii)
65. June 2023 · Paper 1 · Q20(e)(ii)
Mark scheme June 2023 Paper 1 Q20(e)(ii)
66. June 2023 · Paper 1 · Q21(a)(iii)
Mark scheme June 2023 Paper 1 Q21(a)(iii)
67. June 2023 · AS Paper 1 · Q22(c)(iv)
Mark scheme June 2023 Paper 1 Q22(c)(iv)
68. June 2023 · AS Paper 2 · Q1(b)(ii)
Mark scheme June 2023 Paper 2 Q1(b)(ii)
69. June 2023 · AS Paper 2 · Q2(b)(ii)
Mark scheme June 2023 Paper 2 Q2(b)(ii)
70. June 2023 · AS Paper 2 · Q3(a)
Mark scheme June 2023 Paper 2 Q3(a)
71. June 2023 · Paper 2 · Q5
Mark scheme June 2023 Paper 2 Q5
72. June 2023 · Paper 2 · Q8
Mark scheme June 2023 Paper 2 Q8
73. June 2023 · Paper 2 · Q16(b)(iii)
Mark scheme June 2023 Paper 2 Q16(b)(iii)
74. June 2023 · Paper 2 · Q18(b)
Mark scheme June 2023 Paper 2 Q18(b)
75. June 2023 · Paper 2 · Q20(b)(ii)
Mark scheme June 2023 Paper 2 Q20(b)(ii)
76. June 2023 · Paper 2 · Q23
Mark scheme June 2023 Paper 2 Q23
77. June 2023 · Paper 3 · Q1(h)
Mark scheme June 2023 Paper 3 Q1(h)
78. June 2023 · Paper 3 · Q2(a)(ii)
Mark scheme June 2023 Paper 3 Q2(a)(ii)
79. June 2023 · Paper 3 · Q4(b)(i)
Mark scheme June 2023 Paper 3 Q4(b)(i)
80. June 2023 · Paper 3 · Q4(b)(ii)
Mark scheme June 2023 Paper 3 Q4(b)(ii)
81. June 2023 · Paper 3 · Q5(a)
Mark scheme June 2023 Paper 3 Q5(a)
82. June 2023 · Paper 3 · Q6(e)
Mark scheme June 2023 Paper 3 Q6(e)
83. June 2022 · Paper 1 · Q2
Mark scheme June 2022 Paper 1 Q2
84. June 2022 · Paper 1 · Q3
Mark scheme June 2022 Paper 1 Q3
85. June 2022 · Paper 1 · Q4
Mark scheme June 2022 Paper 1 Q4
86. June 2022 · Paper 1 · Q5
Mark scheme June 2022 Paper 1 Q5
87. June 2022 · AS Paper 1 · Q7
Mark scheme June 2022 Paper 1 Q7
88. June 2022 · AS Paper 1 · Q8
Mark scheme June 2022 Paper 1 Q8
89. June 2022 · AS Paper 1 · Q9
Mark scheme June 2022 Paper 1 Q9
90. June 2022 · AS Paper 1 · Q16
Mark scheme June 2022 Paper 1 Q16
91. June 2022 · Paper 1 · Q17(a)(i)
Mark scheme June 2022 Paper 1 Q17(a)(i)
92. June 2022 · Paper 1 · Q18(b)
Mark scheme June 2022 Paper 1 Q18(b)
93. June 2022 · Paper 1 · Q19(a)(ii)
Mark scheme June 2022 Paper 1 Q19(a)(ii)
94. June 2022 · Paper 1 · Q21(b)(i)
Mark scheme June 2022 Paper 1 Q21(b)(i)
95. June 2022 · Paper 1 · Q21(c)(i)
Mark scheme June 2022 Paper 1 Q21(c)(i)
96. June 2022 · Paper 1 · Q22(a)(ii)
Mark scheme June 2022 Paper 1 Q22(a)(ii)
97. June 2022 · AS Paper 1 · Q22(c)
Mark scheme June 2022 Paper 1 Q22(c)
98. June 2022 · Paper 1 · Q22(c)
Mark scheme June 2022 Paper 1 Q22(c)
99. June 2022 · AS Paper 1 · Q25(a)(i)
Mark scheme June 2022 Paper 1 Q25(a)(i)
100. June 2022 · AS Paper 1 · Q26(b)
Mark scheme June 2022 Paper 1 Q26(b)
101. June 2022 · AS Paper 2 · Q1(b)(ii)
Mark scheme June 2022 Paper 2 Q1(b)(ii)
102. June 2022 · AS Paper 2 · Q1(c)
Mark scheme June 2022 Paper 2 Q1(c)
103. June 2022 · AS Paper 2 · Q5(b)
Mark scheme June 2022 Paper 2 Q5(b)
104. June 2022 · AS Paper 2 · Q5(c)(i)
Mark scheme June 2022 Paper 2 Q5(c)(i)
105. June 2022 · Paper 2 · Q6
Mark scheme June 2022 Paper 2 Q6
106. June 2022 · Paper 2 · Q7
Mark scheme June 2022 Paper 2 Q7
107. June 2022 · Paper 2 · Q8
Mark scheme June 2022 Paper 2 Q8
108. June 2022 · Paper 2 · Q9
Mark scheme June 2022 Paper 2 Q9
109. June 2022 · Paper 2 · Q17
Mark scheme June 2022 Paper 2 Q17
110. June 2022 · Paper 2 · Q18(b)
Mark scheme June 2022 Paper 2 Q18(b)
111. June 2022 · Paper 2 · Q19(e)
Mark scheme June 2022 Paper 2 Q19(e)
112. June 2022 · Paper 3 · Q2(a)(i)
Mark scheme June 2022 Paper 3 Q2(a)(i)
113. June 2022 · Paper 3 · Q3(a)
Mark scheme June 2022 Paper 3 Q3(a)
114. June 2022 · Paper 3 · Q5(b)(ii)
Mark scheme June 2022 Paper 3 Q5(b)(ii)
115. June 2022 · Paper 3 · Q6(b)(ii)
Mark scheme June 2022 Paper 3 Q6(b)(ii)
116. June 2022 · Paper 3 · Q6(c)(ii)
Mark scheme June 2022 Paper 3 Q6(c)(ii)
117. June 2022 · Paper 3 · Q6(d)
Mark scheme June 2022 Paper 3 Q6(d)
118. November 2021 · AS Paper 1 · Q4
Mark scheme November 2021 Paper 1 Q4
119. November 2021 · Paper 1 · Q4
Mark scheme November 2021 Paper 1 Q4
120. November 2021 · AS Paper 1 · Q5
Mark scheme November 2021 Paper 1 Q5
121. November 2021 · Paper 1 · Q5
Mark scheme November 2021 Paper 1 Q5
122. November 2021 · AS Paper 1 · Q6
Mark scheme November 2021 Paper 1 Q6
123. November 2021 · Paper 1 · Q6
Mark scheme November 2021 Paper 1 Q6
124. November 2021 · Paper 1 · Q17(b)(ii)
Mark scheme November 2021 Paper 1 Q17(b)(ii)
125. November 2021 · Paper 1 · Q18(d)
Mark scheme November 2021 Paper 1 Q18(d)
126. November 2021 · AS Paper 1 · Q21(d)(ii)
Mark scheme November 2021 Paper 1 Q21(d)(ii)
127. November 2021 · Paper 1 · Q22(b)(i)
Mark scheme November 2021 Paper 1 Q22(b)(i)
128. November 2021 · Paper 1 · Q22(c)
Mark scheme November 2021 Paper 1 Q22(c)
129. November 2021 · AS Paper 1 · Q25(a)(i)
Mark scheme November 2021 Paper 1 Q25(a)(i)
130. November 2021 · AS Paper 1 · Q25(a)(ii)
Mark scheme November 2021 Paper 1 Q25(a)(ii)
131. November 2021 · AS Paper 1 · Q25(b)
Mark scheme November 2021 Paper 1 Q25(b)
132. November 2021 · Paper 2 · Q3
Mark scheme November 2021 Paper 2 Q3
133. November 2021 · AS Paper 2 · Q3(c)
Mark scheme November 2021 Paper 2 Q3(c)
134. November 2021 · AS Paper 2 · Q4(a)
Mark scheme November 2021 Paper 2 Q4(a)
135. November 2021 · AS Paper 2 · Q6(c)(i)
Mark scheme November 2021 Paper 2 Q6(c)(i)
136. November 2021 · AS Paper 2 · Q7(b)
Mark scheme November 2021 Paper 2 Q7(b)
137. November 2021 · Paper 2 · Q18(c)(i)
Mark scheme November 2021 Paper 2 Q18(c)(i)
138. November 2021 · Paper 2 · Q18(c)(ii)
Mark scheme November 2021 Paper 2 Q18(c)(ii)
139. November 2021 · Paper 2 · Q19(b)
Mark scheme November 2021 Paper 2 Q19(b)
140. November 2021 · Paper 2 · Q20(b)(ii)
Mark scheme November 2021 Paper 2 Q20(b)(ii)
141. November 2021 · Paper 3 · Q1(a)
Mark scheme November 2021 Paper 3 Q1(a)
142. November 2021 · Paper 3 · Q1(d)
Mark scheme November 2021 Paper 3 Q1(d)
143. November 2021 · Paper 3 · Q2(a)
Mark scheme November 2021 Paper 3 Q2(a)
144. November 2021 · Paper 3 · Q2(b)
Mark scheme November 2021 Paper 3 Q2(b)
145. November 2021 · Paper 3 · Q2(d)
Mark scheme November 2021 Paper 3 Q2(d)
146. November 2021 · Paper 3 · Q3(a)
Mark scheme November 2021 Paper 3 Q3(a)
147. November 2021 · Paper 3 · Q3(b)
Mark scheme November 2021 Paper 3 Q3(b)
148. November 2021 · Paper 3 · Q5(a)(ii)
Mark scheme November 2021 Paper 3 Q5(a)(ii)
149. November 2021 · Paper 3 · Q5(c)
Mark scheme November 2021 Paper 3 Q5(c)
150. November 2020 · Paper 1 · Q2
Mark scheme November 2020 Paper 1 Q2
151. November 2020 · Paper 1 · Q3
Mark scheme November 2020 Paper 1 Q3
152. November 2020 · Paper 1 · Q4
Mark scheme November 2020 Paper 1 Q4
153. November 2020 · AS Paper 1 · Q9
Mark scheme November 2020 Paper 1 Q9
154. November 2020 · AS Paper 1 · Q10
Mark scheme November 2020 Paper 1 Q10
155. November 2020 · Paper 1 · Q11
Mark scheme November 2020 Paper 1 Q11
156. November 2020 · AS Paper 1 · Q14
Mark scheme November 2020 Paper 1 Q14
157. November 2020 · Paper 1 · Q16(b)(ii)
Mark scheme November 2020 Paper 1 Q16(b)(ii)
158. November 2020 · AS Paper 1 · Q18
Mark scheme November 2020 Paper 1 Q18
159. November 2020 · Paper 1 · Q20(b)
Mark scheme November 2020 Paper 1 Q20(b)
160. November 2020 · Paper 1 · Q21(c)
Mark scheme November 2020 Paper 1 Q21(c)
161. November 2020 · Paper 1 · Q22(b)(i)
Mark scheme November 2020 Paper 1 Q22(b)(i)
162. November 2020 · AS Paper 1 · Q22(c)
Mark scheme November 2020 Paper 1 Q22(c)
163. November 2020 · Paper 1 · Q22(c)
Mark scheme November 2020 Paper 1 Q22(c)
164. November 2020 · AS Paper 1 · Q23(a)
Mark scheme November 2020 Paper 1 Q23(a)
165. November 2020 · AS Paper 1 · Q23(b)(ii)
Mark scheme November 2020 Paper 1 Q23(b)(ii)
166. November 2020 · AS Paper 2 · Q1(b)(i)
Mark scheme November 2020 Paper 2 Q1(b)(i)
167. November 2020 · AS Paper 2 · Q1(b)(ii)
Mark scheme November 2020 Paper 2 Q1(b)(ii)
168. November 2020 · AS Paper 2 · Q1(b)(iii)
Mark scheme November 2020 Paper 2 Q1(b)(iii)
169. November 2020 · AS Paper 2 · Q2(b)
Mark scheme November 2020 Paper 2 Q2(b)
170. November 2020 · AS Paper 2 · Q4(b)(ii)
Mark scheme November 2020 Paper 2 Q4(b)(ii)
171. November 2020 · AS Paper 2 · Q5(d)(i)
Mark scheme November 2020 Paper 2 Q5(d)(i)
172. November 2020 · Paper 2 · Q11
Mark scheme November 2020 Paper 2 Q11
173. November 2020 · Paper 2 · Q12
Mark scheme November 2020 Paper 2 Q12
174. November 2020 · Paper 2 · Q20(a)
Mark scheme November 2020 Paper 2 Q20(a)
175. November 2020 · Paper 2 · Q21(b)(iii)
Mark scheme November 2020 Paper 2 Q21(b)(iii)
176. November 2020 · Paper 2 · Q22(b)
Mark scheme November 2020 Paper 2 Q22(b)
177. November 2020 · Paper 3 · Q1(b)(ii)
Mark scheme November 2020 Paper 3 Q1(b)(ii)
178. November 2020 · Paper 3 · Q3(a)(i)
Mark scheme November 2020 Paper 3 Q3(a)(i)
179. November 2020 · Paper 3 · Q4(a)(iv)
Mark scheme November 2020 Paper 3 Q4(a)(iv)
180. November 2020 · Paper 3 · Q4(b)(i)
Mark scheme November 2020 Paper 3 Q4(b)(i)
181. November 2020 · Paper 3 · Q4(b)(ii)
Mark scheme November 2020 Paper 3 Q4(b)(ii)
182. November 2020 · Paper 3 · Q4(c)(i)
Mark scheme November 2020 Paper 3 Q4(c)(i)
183. November 2020 · Paper 3 · Q4(c)(ii)
Mark scheme November 2020 Paper 3 Q4(c)(ii)
184. June 2019 · Paper 1 · Q3
Mark scheme June 2019 Paper 1 Q3
185. June 2019 · AS Paper 1 · Q4
Mark scheme June 2019 Paper 1 Q4
186. June 2019 · Paper 1 · Q4
Mark scheme June 2019 Paper 1 Q4
187. June 2019 · AS Paper 1 · Q5
Mark scheme June 2019 Paper 1 Q5
188. June 2019 · AS Paper 1 · Q6
Mark scheme June 2019 Paper 1 Q6
189. June 2019 · AS Paper 1 · Q7
Mark scheme June 2019 Paper 1 Q7
190. June 2019 · Paper 1 · Q8
Mark scheme June 2019 Paper 1 Q8
191. June 2019 · Paper 1 · Q10
Mark scheme June 2019 Paper 1 Q10
192. June 2019 · Paper 1 · Q18(c)(ii)
Mark scheme June 2019 Paper 1 Q18(c)(ii)
193. June 2019 · Paper 1 · Q18(c)(iii)
Mark scheme June 2019 Paper 1 Q18(c)(iii)
194. June 2019 · Paper 1 · Q19(b)(ii)
Mark scheme June 2019 Paper 1 Q19(b)(ii)
195. June 2019 · Paper 1 · Q20(b)(i)
Mark scheme June 2019 Paper 1 Q20(b)(i)
196. June 2019 · Paper 1 · Q20(b)(ii)
Mark scheme June 2019 Paper 1 Q20(b)(ii)
197. June 2019 · AS Paper 1 · Q22(b)
Mark scheme June 2019 Paper 1 Q22(b)
198. June 2019 · AS Paper 1 · Q25(b)(iii)
Mark scheme June 2019 Paper 1 Q25(b)(iii)
199. June 2019 · AS Paper 2 · Q1(d)(i)
Mark scheme June 2019 Paper 2 Q1(d)(i)
200. June 2019 · AS Paper 2 · Q1(d)(ii)
Mark scheme June 2019 Paper 2 Q1(d)(ii)
201. June 2019 · AS Paper 2 · Q2(a)
Mark scheme June 2019 Paper 2 Q2(a)
202. June 2019 · AS Paper 2 · Q2(b)
Mark scheme June 2019 Paper 2 Q2(b)
203. June 2019 · AS Paper 2 · Q4(a)
Mark scheme June 2019 Paper 2 Q4(a)
204. June 2019 · AS Paper 2 · Q4(c)
Mark scheme June 2019 Paper 2 Q4(c)
205. June 2019 · AS Paper 2 · Q5(b)(i)
Mark scheme June 2019 Paper 2 Q5(b)(i)
206. June 2019 · Paper 2 · Q11
Mark scheme June 2019 Paper 2 Q11
207. June 2019 · Paper 2 · Q16(b)(ii)
Mark scheme June 2019 Paper 2 Q16(b)(ii)
208. June 2019 · Paper 2 · Q17(a)(ii)
Mark scheme June 2019 Paper 2 Q17(a)(ii)
209. June 2019 · Paper 2 · Q18(e)(i)
Mark scheme June 2019 Paper 2 Q18(e)(i)
210. June 2019 · Paper 2 · Q21
Mark scheme June 2019 Paper 2 Q21
211. June 2019 · Paper 3 · Q1(d)
Mark scheme June 2019 Paper 3 Q1(d)
212. June 2019 · Paper 3 · Q1(f)
Mark scheme June 2019 Paper 3 Q1(f)
213. June 2019 · Paper 3 · Q2(d)
Mark scheme June 2019 Paper 3 Q2(d)
214. June 2019 · Paper 3 · Q3(a)(iv)
Mark scheme June 2019 Paper 3 Q3(a)(iv)
215. June 2019 · Paper 3 · Q4(a)(iv)
Mark scheme June 2019 Paper 3 Q4(a)(iv)
216. June 2019 · Paper 3 · Q5(a)(i)
Mark scheme June 2019 Paper 3 Q5(a)(i)
217. June 2019 · Paper 3 · Q6(b)
Mark scheme June 2019 Paper 3 Q6(b)
218. June 2018 · AS Paper 1 · Q2
Mark scheme June 2018 Paper 1 Q2
219. June 2018 · AS Paper 1 · Q3
Mark scheme June 2018 Paper 1 Q3
220. June 2018 · Paper 1 · Q3
Mark scheme June 2018 Paper 1 Q3
221. June 2018 · AS Paper 1 · Q4
Mark scheme June 2018 Paper 1 Q4
222. June 2018 · Paper 1 · Q4
Mark scheme June 2018 Paper 1 Q4
223. June 2018 · AS Paper 1 · Q17
Mark scheme June 2018 Paper 1 Q17
224. June 2018 · Paper 1 · Q19(b)
Mark scheme June 2018 Paper 1 Q19(b)
225. June 2018 · Paper 1 · Q20(c)
Mark scheme June 2018 Paper 1 Q20(c)
226. June 2018 · Paper 1 · Q20(d)(iv)
Mark scheme June 2018 Paper 1 Q20(d)(iv)
227. June 2018 · Paper 1 · Q21(d)
Mark scheme June 2018 Paper 1 Q21(d)
228. June 2018 · AS Paper 1 · Q22(a)(ii)
Mark scheme June 2018 Paper 1 Q22(a)(ii)
229. June 2018 · AS Paper 1 · Q22(b)(i)
Mark scheme June 2018 Paper 1 Q22(b)(i)
230. June 2018 · AS Paper 1 · Q23(a)(i)
Mark scheme June 2018 Paper 1 Q23(a)(i)
231. June 2018 · AS Paper 2 · Q1(d)(i)
Mark scheme June 2018 Paper 2 Q1(d)(i)
232. June 2018 · AS Paper 2 · Q4(a)(ii)
Mark scheme June 2018 Paper 2 Q4(a)(ii)
233. June 2018 · AS Paper 2 · Q5(a)(ii)
Mark scheme June 2018 Paper 2 Q5(a)(ii)
234. June 2018 · Paper 2 · Q7
Mark scheme June 2018 Paper 2 Q7
235. June 2018 · Paper 2 · Q19(c)(ii)
Mark scheme June 2018 Paper 2 Q19(c)(ii)
236. June 2018 · Paper 2 · Q21(c)(i)
Mark scheme June 2018 Paper 2 Q21(c)(i)
237. June 2018 · Paper 2 · Q22(c)(i)
Mark scheme June 2018 Paper 2 Q22(c)(i)
238. June 2018 · Paper 2 · Q22(d)
Mark scheme June 2018 Paper 2 Q22(d)
239. June 2018 · Paper 3 · Q1(a)(viii)
Mark scheme June 2018 Paper 3 Q1(a)(viii)
240. June 2018 · Paper 3 · Q2(a)(ii)
Mark scheme June 2018 Paper 3 Q2(a)(ii)
241. June 2018 · Paper 3 · Q3(b)(ii)
Mark scheme June 2018 Paper 3 Q3(b)(ii)
242. June 2018 · Paper 3 · Q4(b)(ii)
Mark scheme June 2018 Paper 3 Q4(b)(ii)
243. June 2018 · Paper 3 · Q5(a)
Mark scheme June 2018 Paper 3 Q5(a)
244. June 2017 · AS Paper 1 · Q2
Mark scheme June 2017 Paper 1 Q2
245. June 2017 · AS Paper 1 · Q3
Mark scheme June 2017 Paper 1 Q3
246. June 2017 · AS Paper 1 · Q4
Mark scheme June 2017 Paper 1 Q4
247. June 2017 · Paper 1 · Q5
Mark scheme June 2017 Paper 1 Q5
248. June 2017 · Paper 1 · Q6
Mark scheme June 2017 Paper 1 Q6
249. June 2017 · Paper 1 · Q7
Mark scheme June 2017 Paper 1 Q7
250. June 2017 · Paper 1 · Q12
Mark scheme June 2017 Paper 1 Q12
251. June 2017 · AS Paper 1 · Q15
Mark scheme June 2017 Paper 1 Q15
252. June 2017 · Paper 1 · Q19(a)
Mark scheme June 2017 Paper 1 Q19(a)
253. June 2017 · Paper 1 · Q21(c)(i)
Mark scheme June 2017 Paper 1 Q21(c)(i)
254. June 2017 · AS Paper 1 · Q22(c)(ii)
Mark scheme June 2017 Paper 1 Q22(c)(ii)
255. June 2017 · Paper 1 · Q23(b)
Mark scheme June 2017 Paper 1 Q23(b)
256. June 2017 · AS Paper 1 · Q24(c)(i)
Mark scheme June 2017 Paper 1 Q24(c)(i)
257. June 2017 · AS Paper 1 · Q25(b)
Mark scheme June 2017 Paper 1 Q25(b)
258. June 2017 · AS Paper 2 · Q1(a)(iii)
Mark scheme June 2017 Paper 2 Q1(a)(iii)
259. June 2017 · AS Paper 2 · Q1(b)(iii)
Mark scheme June 2017 Paper 2 Q1(b)(iii)
260. June 2017 · AS Paper 2 · Q2
Mark scheme June 2017 Paper 2 Q2
261. June 2017 · Paper 2 · Q3
Mark scheme June 2017 Paper 2 Q3
262. June 2017 · AS Paper 2 · Q3(a)(i)
Mark scheme June 2017 Paper 2 Q3(a)(i)
263. June 2017 · AS Paper 2 · Q3(b)(ii)
Mark scheme June 2017 Paper 2 Q3(b)(ii)
264. June 2017 · Paper 2 · Q5
Mark scheme June 2017 Paper 2 Q5
265. June 2017 · AS Paper 2 · Q6(a)(ii)
Mark scheme June 2017 Paper 2 Q6(a)(ii)
266. June 2017 · Paper 2 · Q9
Mark scheme June 2017 Paper 2 Q9
267. June 2017 · Paper 2 · Q12
Mark scheme June 2017 Paper 2 Q12
268. June 2017 · Paper 2 · Q16(e)(i)
Mark scheme June 2017 Paper 2 Q16(e)(i)
269. June 2017 · Paper 2 · Q16(e)(ii)
Mark scheme June 2017 Paper 2 Q16(e)(ii)
270. June 2017 · Paper 2 · Q17(a)(ii)
Mark scheme June 2017 Paper 2 Q17(a)(ii)
271. June 2017 · Paper 2 · Q20(a)
Mark scheme June 2017 Paper 2 Q20(a)
272. June 2017 · Paper 3 · Q1(c)
Mark scheme June 2017 Paper 3 Q1(c)
273. June 2017 · Paper 3 · Q1(d)
Mark scheme June 2017 Paper 3 Q1(d)
274. June 2017 · Paper 3 · Q2(a)
Mark scheme June 2017 Paper 3 Q2(a)
275. June 2017 · Paper 3 · Q3(c)(ii)
Mark scheme June 2017 Paper 3 Q3(c)(ii)
276. June 2017 · Paper 3 · Q4(a)(ii)
Mark scheme June 2017 Paper 3 Q4(a)(ii)
277. June 2017 · Paper 3 · Q4(c)(ii)
Mark scheme June 2017 Paper 3 Q4(c)(ii)
278. June 2016 · AS Paper 1 · Q3
Mark scheme June 2016 Paper 1 Q3
279. June 2016 · AS Paper 1 · Q21(b)(ii)
Mark scheme June 2016 Paper 1 Q21(b)(ii)
280. June 2016 · AS Paper 1 · Q22(a)
Mark scheme June 2016 Paper 1 Q22(a)
281. June 2016 · AS Paper 1 · Q22(b)(iii)
Mark scheme June 2016 Paper 1 Q22(b)(iii)
282. June 2016 · AS Paper 1 · Q22(c)
Mark scheme June 2016 Paper 1 Q22(c)
283. June 2016 · AS Paper 1 · Q24(a)
Mark scheme June 2016 Paper 1 Q24(a)
284. June 2016 · AS Paper 1 · Q24(c)
Mark scheme June 2016 Paper 1 Q24(c)
285. June 2016 · AS Paper 1 · Q26(c)(i)
Mark scheme June 2016 Paper 1 Q26(c)(i)
286. June 2016 · AS Paper 2 · Q1(c)(i)
Mark scheme June 2016 Paper 2 Q1(c)(i)
287. June 2016 · AS Paper 2 · Q1(c)(ii)
Mark scheme June 2016 Paper 2 Q1(c)(ii)
288. June 2016 · AS Paper 2 · Q1(d)
Mark scheme June 2016 Paper 2 Q1(d)
289. June 2016 · AS Paper 2 · Q4(b)
Mark scheme June 2016 Paper 2 Q4(b)
290. June 2016 · AS Paper 2 · Q5(a)(ii)
Mark scheme June 2016 Paper 2 Q5(a)(ii)
291. June 2016 · AS Paper 2 · Q6(d)
Mark scheme June 2016 Paper 2 Q6(d)