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Equilibrium constants Kc and Kp

Past-paper questions pack

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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 · 45 parts · mark schemes follow the questions · www.chemistryaleveltutor.com · Questions and mark schemes © OCR

1. June 2025 · Paper 1 · Q17(c)(i) · 1 marks ·
(c) Steam can be reduced by carbon monoxide in a reversible reaction. H2O(g) + CO(g) H2(g) + CO2(g) Equilibrium 17.3 ΔH = –39.9 kJ mol–1 At 700 K the value of Kp is 8.13. (i) Explain why Kp for Equilibrium 17.3 has no units. .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [1]
2. June 2025 · Paper 1 · Q17(c)(ii) · 3 marks ·
(ii) An equal number of moles of steam and carbon monoxide are left at 700 K in a sealed container until equilibrium is reached. At equilibrium, both H2 and CO2 have a partial pressure of 211 kPa. Calculate the partial pressures of H2O and CO at equilibrium. Partial pressure of H2O = ........................................................ kPa Partial pressure of CO = ........................................................ kPa [3]
3. June 2025 · Paper 1 · Q17(c)(iii) · 2 marks ·
(iii) At a second temperature the value of Kp for Equilibrium 17.3 is 129. Explain whether the second temperature is higher or lower than 700 K. .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [2]
4. June 2025 · Paper 3 · Q3(a) · 5 marks ·
3 This question is about equilibrium and rates. (a) Methanol, CH3OH, can be made industrially by the reaction of carbon monoxide, CO, with hydrogen, H2, in the presence of a catalyst. This is a reversible reaction. The equilibrium below is set up. CO(g) + 2H2(g) CH3OH(g) ∆H = –91 kJ mol–1 The concentrations of CO(g) and CH3OH(g) in the equilibrium mixture are shown in the table below. CO(g) CH3OH(g) equilibrium concentration / mol dm–3 0.27 0.11 The value of the equilibrium constant, Kc, for this reaction is 1.8 dm6 mol–2. • Explain the conditions of pressure and temperature that would give the maximum equilibrium yield of CH3OH(g). • Calculate the concentration of H2(g) in the equilibrium mixture to an appropriate number of significant figures. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [5]
5. June 2024 · Paper 1 · Q18(a)(i) · 5 marks ·
18 This question is about two oxides of sulfur: sulfur dioxide, SO2, and sulfur trioxide, SO3. (a) SO3 decomposes to form SO2 and O2, as shown in Equilibrium 18.1. SO3(g) SO2(g) + 1 2O2(g) ∆H = +99 kJ mol–1 Equilibrium 18.1 (i) 2.25 moles of SO3 is heated to 550 °C in the presence of a catalyst and the resulting mixture allowed to reach equilibrium. The equilibrium mixture contains 0.900 mol of SO2 and the total pressure is 2.80 atm. Calculate the numerical value for Kp for Equilibrium 18.1 under these conditions and state the units of Kp. Give your answer to 3 significant figures. Kp = ............................................................... units .......................................................... [5]
6. June 2024 · Paper 1 · Q18(a)(ii) · 2 marks ·
(ii) The numerical values of Kp for Equilibrium 18.1 at temperatures T1 and T2 are shown below. Temperature Kp T1 3.3 × 10–5 T2 7.7 × 10–2 Explain why T2 is a higher temperature than T1. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... ..................................................................................................................................................... [2]
7. June 2024 · Paper 1 · Q18(a)(iii) · 2 marks ·
(iii) Suggest how the value of Kp would change if the reaction was repeated with no catalyst added and the pressure of the system increased. Tick (✓) one box in each row. Change Decrease No change Increase No catalyst Increased pressure [2]
8. June 2023 · Paper 1 · Q19(a)(i) · 5 marks · AO1, 2
19 This question is about oxides of nitrogen. (a) An investigation is carried out on the equilibrium system shown below. 2NO2(g) N2O4(g) ∆H = –57.4 kJ mol–1 (i) A sealed flask containing 6.00 moles of NO2(g) is heated to a constant temperature and allowed to reach equilibrium. The equilibrium mixture contains 5.40 mol of NO2(g), and the total pressure is 5.00 atm. Determine the value of Kp and give your answer to 3 significant figures. Include an expression for Kp and the units of Kp in your answer. Kp = ............................................... units ......................[5]
9. June 2023 · Paper 1 · Q19(a)(ii) · 3 marks · AO2, 3
(ii) The sealed flask in (a)(i) is then heated to a higher temperature at an increased pressure. The system is allowed to reach equilibrium again. Explain why it is difficult to predict how these changes in reaction conditions affect the amount of N2O4(g) formed at equilibrium. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [3]
10. June 2023 · Paper 3 · Q6(d) · 5 marks · AO1, 2
(d) In the UK, most sulfuric acid, H2SO4, is manufactured by the Contact process. One stage in the Contact process involves the equilibrium between sulfur dioxide, oxygen and sulfur trioxide. 2SO2(g) + O2(g) 2SO3(g) This equilibrium is investigated: Step 1 5.82 × 10–2 mol of SO2 is mixed with 7.40 × 10–2 mol of O2 in a 2.00 dm3 container. Step 2 The container is sealed and allowed to reach equilibrium at constant temperature. Step 3 At equilibrium, 5.20 × 10–2 mol of SO3 is formed. Determine the equilibrium concentrations and calculate Kc, including units. Kc = ........................ units ........................ [5]
11. June 2022 · Paper 1 · Q20(a) · 6 marks · AO1, 2
20 This question is about equilibria involving hydrogen. (a)* Hydrogen is used industrially to manufacture ammonia. The equilibrium is shown below. N2(g) + 3H2(g) 2NH3(g) ∆H = –92 kJ mol–1 Equilibrium 20.1 1.20 mol N2(g) is mixed with 3.60 mol H2(g) in a 8.00 dm3 container. The mixture is heated to 550 °C with an iron catalyst and allowed to reach equilibrium. The equilibrium mixture contains 0.160 mol of NH3. Determine the equilibrium constant Kc for Equilibrium 20.1, and explain why the operational conditions used by industry may be different from those required for a maximum equilibrium yield of ammonia. [6] ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Additional answer space if required. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................
12. June 2022 · Paper 1 · Q20(b)(i) · 1 marks · AO1
(b) In industry, hydrogen is also used to reduce the iron oxide Fe3O4 as shown in Equilibrium 20.2. The reaction is carried out at 500 °C. Fe3O4(s) + 4H2(g) 3Fe(s) + 4H2O(g) Equilibrium 20.2 (i) When the temperature is decreased, the value of Kp decreases. Determine whether the forward reaction is exothermic or endothermic. Explain your answer. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1]
13. June 2022 · Paper 1 · Q20(b)(ii) · 1 marks · AO3
(ii) Two students are discussing the effect of pressure on the equilibrium position of Equilibrium 20.2. Student 1 says: “There are more moles of products than reactants, so increasing the pressure will shift the equilibrium to the left hand side.” Student 2 disagrees. Determine which student is correct. Justify your answer. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1]
14. June 2022 · Paper 3 · Q4(b)(ii) · 3 marks · AO3
(ii) Explain the changes in concentration of CoCl 4 2–, Cl – and [Co(H2O)6]2+ after time = t1. Refer to Equilibrium 4.1 in your answer. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [3]
15. November 2021 · Paper 1 · Q9 · 1 marks ·
9 An equilibrium system is shown below. CO(g) + NO2(g) CO2(g) + NO(g) Different amounts of CO, NO2, CO2 and NO are added to four containers, as shown below. Container CO / mol NO2 / mol CO2 / mol NO / mol A 1 1 0 0 B 1 0 1 1 C 1 1 1 0 D 0 1 1 1 Which container would have the largest concentration of CO(g) at equilibrium? Your answer [1]
16. November 2021 · Paper 1 · Q20(c)(i) · 4 marks · AO2
(c) A chemist investigates the equilibrium shown in Equilibrium 20.1. The chemist mixes together 1.60 mol of NO(g) and 1.50 mol of O2(g) in a container and the mixture is allowed to reach equilibrium. At equilibrium: • 75% of the NO(g) has been converted to NO2(g) • the total pressure is 1.21 MPa. (i) Calculate Kp, in MPa–1, for Equilibrium 20.1. Give your answer to 3 significant figures. Kp = .............................................. MPa–1 [4]
17. November 2021 · Paper 1 · Q20(c)(ii) · 3 marks · AO1
(ii) The chemist then repeats the experiment three times. In each experiment, the chemist makes one change but uses the same initial amounts of NO and O2. Complete the table to show the predicted effect of each change compared with the original experiment. Only use the words greater, smaller or same. Equilibrium amount Change Kp Initial rate of NO2(g) Temperature increase Pressure increase Catalyst added [3]
18. 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]
19. November 2021 · Paper 3 · Q1(b) · 2 marks · AO1, 2
(b) Pure PCl5 is placed in a sealed container which is heated to 200 ºC. An equilibrium is set up: PCl5(g) PCl3(g) + Cl2(g) Under these conditions: • Kc = 8.00 × 10–3 mol dm–3 • equilibrium concentration of PCl5 = 0.0500 mol dm–3. Calculate the concentrations of PCl3 and Cl2 at equilibrium. concentration of PCl3 = ................................................ mol dm–3 concentration of Cl2 = ................................................ mol dm–3 [2]
20. November 2020 · Paper 1 · Q9 · 1 marks · AO2
9 The reversible reaction of nitrogen and hydrogen to form ammonia is shown below. N2(g) + 3H2(g) 2NH3(g) In the equilibrium mixture, the partial pressure of N2 is 18.75 MPa and the partial pressure of H2 is 2.50 MPa. The total pressure is 25 MPa. What is the value of Kp, in MPa−2? A 1.2 × 10−4 B 0.048 C 0.075 D 21 Your answer [1]
21. November 2020 · Paper 1 · Q13 · 1 marks · AO1
13 Which statement(s) is/are correct when a catalyst is added to a system in dynamic equilibrium? 1 The rates of the forward and reverse reactions increase by the same amount. 2 The concentrations of the reactants and products do not change. 3 The value of Kc increases. A 1, 2 and 3 B Only 1 and 2 C Only 2 and 3 D Only 1 Your answer [1]
22. November 2020 · Paper 1 · Q17(d) · 3 marks · AO1, 3
(d) At 298 K, the free energy change, ∆G, for the production of methanol in equilibrium 1 is −2.48 × 104 J mol−1. ∆G is linked to Kp by the relationship: ∆G = −RT lnKp. R = gas constant T = temperature in K. Calculate Kp for equilibrium 1 at 298 K. Give your answer to 3 significant figures. Kp = .......................... units ...................... [3]
23. 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]
24. November 2020 · Paper 3 · Q5(a) · 2 marks · AO1
5 The equilibrium constant Kp and temperature T (in K) are linked by the mathematical relationship shown in equation 5.1 (R = Gas constant in J mol−1 K−1 and ∆H is enthalpy change in J mol−1). ln Kp = – ∆H R × 1 T + ∆S R Equation 5.1 (a) The table shows the values of Kp at different temperatures for an equilibrium. Complete the table by adding the missing values of 1 T and ln Kp. Temperature, T / K 400 500 600 700 800 Kp 3.00 × 1058 5.86 × 1045 1.83 × 1037 1.46 × 1031 1.14 × 1026 1 T / K−1 2.50 × 10−3 ...................... ...................... ...................... ...................... ln Kp 135 ...................... ...................... ...................... ...................... [2]
25. November 2020 · Paper 3 · Q5(b) · 1 marks · AO2
(b) State and explain how increasing the temperature affects the position of this equilibrium and whether the forward reaction is exothermic or endothermic. ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [1]
26. November 2020 · Paper 3 · Q5(c) · 4 marks · AO3
(c) Plot a graph of ln Kp against 1 T using the axes provided on the opposite page. Use your graph and equation 5.1 to determine ∆H, in kJ mol−1, for this equilibrium. Give your answer to 3 significant figures. ∆H = ........................................... kJ mol−1 [4]
27. June 2019 · Paper 1 · Q19(b)(i) · 2 marks · AO1
(b) The second step in the manufacture of sulfuric acid is the conversion of SO2 into sulfur trioxide, SO3, using Equilibrium 1. 2SO2(g) + O2(g) 2SO3(g)      ∆H = −197 kJ mol−1 Equilibrium 1 An industrial chemist carries out some research into Equilibrium 1. • The chemist fills a 10.2 dm3 container with SO2(g) at RTP, and then adds 12.0 g of O2(g). • The chemist adds the vanadium(V) oxide catalyst, and heats the mixture. The mixture is allowed to reach equilibrium at a pressure of 2.50 atm and a temperature of 1000 K. • A sample of the equilibrium mixture is analysed, and found to contain 0.350 mol of SO3. (i) Write an expression for Kp for Equilibrium 1. Include the units. units = ......................................................... [2]
28. 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]
29. June 2019 · Paper 1 · Q19(b)(iii) · 2 marks · AO3
(iii) The chemist repeats the experiment in (b) at a different temperature. The chemist finds that the value of Kp is greater than the answer to (b)(ii). Explain whether the temperature in the second experiment is higher or lower than 1000 K. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2]
30. June 2019 · Paper 1 · Q19(b)(iv) · 1 marks · AO3
(iv) Explain the significance of the expression: Kp & 1. ........................................................................................................................................... ...................................................................................................................................... [1]
31. June 2019 · Paper 3 · Q1(c) · 1 marks · AO2
(c) What is the partial pressure of O2 (in Pa) in a gas mixture containing 21% O2 by volume and with a total pressure of 1.0 × 105 Pa? partial pressure of O2 = .................................................... Pa [1]
32. June 2018 · Paper 1 · Q9 · 1 marks · AO1
9 The reversible reaction of sulfur dioxide and oxygen to form sulfur trioxide is shown below. 2SO2(g) + O2(g) 2SO3(g) An equilibrium mixture contains 2.4 mol SO2, 1.2 mol O2 and 0.4 mol SO3. The total pressure is 250 atm. What is the partial pressure of SO3? A 15 atm B 25 atm C 100 atm D 200 atm Your answer [1]
33. June 2018 · Paper 1 · Q18(a) · 2 marks ·
18 Nitrogen monoxide, NO, and oxygen, O2, react to form nitrogen dioxide, NO2, in the reversible reaction shown in equilibrium 18.1. 2NO(g) + O2(g) 2NO2(g) Equilibrium 18.1 (a) Write an expression for Kc for this equilibrium and state the units. Kc = Units = ........................ [2]
34. June 2018 · Paper 1 · Q18(b) · 4 marks ·
(b) A chemist mixes together nitrogen and oxygen and pressurises the gases so that their total gas volume is 4.0 dm3. • The mixture is allowed to reach equilibrium at constant temperature and volume. • The equilibrium mixture contains 0.40 mol NO and 0.80 mol O2. • Under these conditions, the numerical value of Kc is 45. Calculate the amount, in mol, of NO2 in the equilibrium mixture. amount of NO2 = ................................................... mol [4]
35. June 2018 · Paper 1 · Q18(c)(i) · 1 marks ·
(c) The values of Kp for equilibrium 18.1 at 298 K and 1000 K are shown below. 2NO(g) + O2(g) 2NO2(g) Equilibrium 18.1 Temperature / K Kp / atm–1 298 Kp = 2.19 × 1012 1000 Kp = 2.03 × 10–1 (i) Predict, with a reason, whether the forward reaction is exothermic or endothermic. ........................................................................................................................................... ...................................................................................................................................... [1]
36. June 2018 · Paper 1 · Q18(c)(ii) · 3 marks ·
(ii) The chemist increases the pressure of the equilibrium mixture at the same temperature. State, and explain in terms of Kp, how you would expect the equilibrium position to change. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [3]
37. June 2018 · Paper 3 · Q5(b)(i) · 1 marks ·
(b) Succinic acid is esterified by ethanol, C2H5OH, in the presence of an acid catalyst to form an equilibrium mixture. The equilibrium constant, Kc, for this equilibrium can be calculated using the amounts, in moles, of the components in the equilibrium mixture, using expression 5.1. n( (CH2COOC2H5)2 ) × n( H2O )2 Kc = n( (CH2COOH)2 ) × n( C2H5OH )2 Expression 5.1 A student carries out an experiment to determine the value of Kc for this equilibrium. • The student mixes together 0.0500 mol of succinic acid and 0.150 mol of ethanol, with a small amount of an acid catalyst. • The mixture is allowed to reach equilibrium. • The student determines that 0.0200 mol of succinic acid are present in the equilibrium mixture. (i) Which technique could be used to determine the equilibrium amount of succinic acid? ...................................................................................................................................... [1]
38. June 2018 · Paper 3 · Q5(b)(iv) · 1 marks ·
(iv) Kc is the equilibrium constant in terms of equilibrium concentrations. Why can expression 5.1 be used to calculate Kc for this equilibrium? ........................................................................................................................................... ...................................................................................................................................... [1]
39. June 2018 · Paper 3 · Q5(b)(v) · 3 marks ·
(v) Calculate the value of Kc for this reaction. Show your working. Kc = ......................................................... [3]
40. June 2017 · Paper 1 · Q13 · 1 marks ·
13 A mixture of N2 and O2 gases has a total pressure of 1.42 atm. The mole fraction of N2 is 0.700. What is the partial pressure, in atm, of O2 in the mixture? A 0.211 B 0.426 C 0.493 D 0.994 Your answer [1]
41. June 2017 · Paper 1 · Q18(b)(i) · 1 marks ·
(b) Iron can be extracted from its ore Fe3O4 using carbon. Several equilibria are involved including equilibrium 18.1, shown below. equilibrium 18.1 Fe3O4(s) + 4C(s) 3Fe(s) + 4CO(g) ∆H = +676.4 kJ mol–1 ∆S = +703.1 J K–1 mol–1 (i) Why is equilibrium 18.1 a heterogeneous equilibrium? ........................................................................................................................................... ...................................................................................................................................... [1]
42. June 2017 · Paper 1 · Q18(b)(ii) · 1 marks ·
(ii) Write the expression for Kp for equilibrium 18.1. [1]
43. June 2017 · Paper 1 · Q20(b)(i) · 2 marks ·
(b) A chemist investigates the equilibrium reaction between sulfur dioxide, oxygen, and sulfur trioxide, shown below. 2SO2(g) + O2(g) 2SO3(g) • The chemist mixes together SO2 and O2 with a catalyst. • The chemist compresses the gas mixture to a volume of 400 cm3. • The mixture is heated to a constant temperature and is allowed to reach equilibrium without changing the total gas volume. The equilibrium mixture contains 0.0540 mol SO2 and 0.0270 mol O2. At the temperature used, the numerical value for Kc is 3.045 × 104 dm3 mol–1. (i) Write the expression for Kc and the units of Kc for this equilibrium. [2]
44. June 2017 · Paper 1 · Q20(b)(ii) · 4 marks ·
(ii) Determine the amount, in mol, of SO3 in the equilibrium mixture at this temperature. Give your final answer to an appropriate number of significant figures. Show all your working. equilibrium amount of SO3 = ................................................... mol [4]
45. 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]

Mark schemes

1. June 2025 · Paper 1 · Q17(c)(i)
Mark scheme June 2025 Paper 1 Q17(c)(i)
2. June 2025 · Paper 1 · Q17(c)(ii)
Mark scheme June 2025 Paper 1 Q17(c)(ii)
3. June 2025 · Paper 1 · Q17(c)(iii)
Mark scheme June 2025 Paper 1 Q17(c)(iii)
4. June 2025 · Paper 3 · Q3(a)
Mark scheme June 2025 Paper 3 Q3(a)
5. June 2024 · Paper 1 · Q18(a)(i)
Mark scheme June 2024 Paper 1 Q18(a)(i)
6. June 2024 · Paper 1 · Q18(a)(ii)
Mark scheme June 2024 Paper 1 Q18(a)(ii)
7. June 2024 · Paper 1 · Q18(a)(iii)
Mark scheme June 2024 Paper 1 Q18(a)(iii)
8. June 2023 · Paper 1 · Q19(a)(i)
Mark scheme June 2023 Paper 1 Q19(a)(i)
9. June 2023 · Paper 1 · Q19(a)(ii)
Mark scheme June 2023 Paper 1 Q19(a)(ii)
10. June 2023 · Paper 3 · Q6(d)
Mark scheme June 2023 Paper 3 Q6(d)
11. June 2022 · Paper 1 · Q20(a)
Mark scheme June 2022 Paper 1 Q20(a)
12. June 2022 · Paper 1 · Q20(b)(i)
Mark scheme June 2022 Paper 1 Q20(b)(i)
13. June 2022 · Paper 1 · Q20(b)(ii)
Mark scheme June 2022 Paper 1 Q20(b)(ii)
14. June 2022 · Paper 3 · Q4(b)(ii)
Mark scheme June 2022 Paper 3 Q4(b)(ii)
15. November 2021 · Paper 1 · Q9
Mark scheme November 2021 Paper 1 Q9
16. November 2021 · Paper 1 · Q20(c)(i)
Mark scheme November 2021 Paper 1 Q20(c)(i)
17. November 2021 · Paper 1 · Q20(c)(ii)
Mark scheme November 2021 Paper 1 Q20(c)(ii)
18. November 2021 · Paper 3 · Q1(a)
Mark scheme November 2021 Paper 3 Q1(a)
19. November 2021 · Paper 3 · Q1(b)
Mark scheme November 2021 Paper 3 Q1(b)
20. November 2020 · Paper 1 · Q9
Mark scheme November 2020 Paper 1 Q9
21. November 2020 · Paper 1 · Q13
Mark scheme November 2020 Paper 1 Q13
22. November 2020 · Paper 1 · Q17(d)
Mark scheme November 2020 Paper 1 Q17(d)
23. November 2020 · Paper 1 · Q20(b)
Mark scheme November 2020 Paper 1 Q20(b)
24. November 2020 · Paper 3 · Q5(a)
Mark scheme November 2020 Paper 3 Q5(a)
25. November 2020 · Paper 3 · Q5(b)
Mark scheme November 2020 Paper 3 Q5(b)
26. November 2020 · Paper 3 · Q5(c)
Mark scheme November 2020 Paper 3 Q5(c)
27. June 2019 · Paper 1 · Q19(b)(i)
Mark scheme June 2019 Paper 1 Q19(b)(i)
28. June 2019 · Paper 1 · Q19(b)(ii)
Mark scheme June 2019 Paper 1 Q19(b)(ii)
29. June 2019 · Paper 1 · Q19(b)(iii)
Mark scheme June 2019 Paper 1 Q19(b)(iii)
30. June 2019 · Paper 1 · Q19(b)(iv)
Mark scheme June 2019 Paper 1 Q19(b)(iv)
31. June 2019 · Paper 3 · Q1(c)
Mark scheme June 2019 Paper 3 Q1(c)
32. June 2018 · Paper 1 · Q9
Mark scheme June 2018 Paper 1 Q9
33. June 2018 · Paper 1 · Q18(a)
Mark scheme June 2018 Paper 1 Q18(a)
34. June 2018 · Paper 1 · Q18(b)
Mark scheme June 2018 Paper 1 Q18(b)
35. June 2018 · Paper 1 · Q18(c)(i)
Mark scheme June 2018 Paper 1 Q18(c)(i)
36. June 2018 · Paper 1 · Q18(c)(ii)
Mark scheme June 2018 Paper 1 Q18(c)(ii)
37. June 2018 · Paper 3 · Q5(b)(i)
Mark scheme June 2018 Paper 3 Q5(b)(i)
38. June 2018 · Paper 3 · Q5(b)(iv)
Mark scheme June 2018 Paper 3 Q5(b)(iv)
39. June 2018 · Paper 3 · Q5(b)(v)
Mark scheme June 2018 Paper 3 Q5(b)(v)
40. June 2017 · Paper 1 · Q13
Mark scheme June 2017 Paper 1 Q13
41. June 2017 · Paper 1 · Q18(b)(i)
Mark scheme June 2017 Paper 1 Q18(b)(i)
42. June 2017 · Paper 1 · Q18(b)(ii)
Mark scheme June 2017 Paper 1 Q18(b)(ii)
43. June 2017 · Paper 1 · Q20(b)(i)
Mark scheme June 2017 Paper 1 Q20(b)(i)
44. June 2017 · Paper 1 · Q20(b)(ii)
Mark scheme June 2017 Paper 1 Q20(b)(ii)
45. June 2017 · Paper 3 · Q3(c)(ii)
Mark scheme June 2017 Paper 3 Q3(c)(ii)