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Kinetics: OCR A‑Level Chemistry B questions

Every OCR A-Level Chemistry B exam question on OZ Kinetics (specification points OZ(e)–(h)), 2016–2025, with its mark scheme and examiner’s report.

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2,049 questions

  1. Q31(c)(iii)

    June 2025 · Paper 1

    3 marksOZ Kinetics
    The whole paper ↗
    June 2025 Paper 1, question 31(c)(iii): Catalysis can be explained using a Boltzmann distribution. Use the diagram to explain how a catalyst speeds up a reaction. Label the diagram and write on the li

  2. Q5

    June 2025 · AS Paper 1

    1 markOZ Kinetics
    The whole paper ↗
    June 2025 AS Paper 1, question 5: A student is measuring the effect of temperature on the rate of reaction of hydrochloric acid with calcium carbonate. What is a variable that must be controlled

  3. Q1(b)

    June 2025 · AS Paper 2

    6 marksOZ Kinetics
    The whole paper ↗
    June 2025 AS Paper 2, question 1(b): Catalytic converters on cars use metals such as platinum as heterogeneous catalysts. Catalytic converters turn exhaust emissions such as carbon monoxide and nit

  4. Q33(d)(ii)

    June 2024 · Paper 1

    2 marksOZ Kinetics
    The whole paper ↗
    June 2024 Paper 1, question 33(d)(ii): Draw an enthalpy profile diagram for the reaction in Equation 33.1 and label the catalysed and uncatalysed reactions. Show the reactants and products and the ac

  5. Q24(a)(i)

    June 2024 · AS Paper 1

    1 markOZ Kinetics
    The whole paper ↗
    June 2024 AS Paper 1, question 24(a)(i): Fill in the missing value in the table. [1]

  6. Q24(a)(ii)

    June 2024 · AS Paper 1

    3 marksOZ Kinetics
    The whole paper ↗
    June 2024 AS Paper 1, question 24(a)(ii): On the graph paper below, plot a graph of rate against volume of sodium thiosulfate, including the origin. Label the axes. Draw a line of best fit. [3]

  7. Q24(a)(iii)

    June 2024 · AS Paper 1

    1 markOZ Kinetics
    The whole paper ↗
    June 2024 AS Paper 1, question 24(a)(iii): Explain why ‘volume of sodium thiosulfate’ is proportional to ‘concentration of sodium thiosulfate’. [1]

  8. Q24(a)(iv)

    June 2024 · AS Paper 1

    2 marksOZ Kinetics
    The whole paper ↗
    June 2024 AS Paper 1, question 24(a)(iv): The graph shows the relationship between rate and thiosulfate concentration for the reaction in Equation 24.1. Describe this relationship and explain it in term

  9. Q24(b)

    June 2024 · AS Paper 1

    2 marksOZ Kinetics
    The whole paper ↗
    June 2024 AS Paper 1, question 24(b): The students repeat the experiment, varying the temperature. They find that the reaction gets faster as the temperature is increased. Complete and label the dia

  10. Q1(b)(iii)

    June 2023 · Paper 3

    1 markOZ Kinetics
    The whole paper ↗
    June 2023 Paper 3, question 1(b)(iii): The diagram below represents an energy profile for the catalysed reaction in Equation 1.1. enthalpy reactants products progress of reaction On the diagram: • In

  11. Q1(c)

    June 2023 · Paper 3

    2 marksOZ Kinetics
    The whole paper ↗
    June 2023 Paper 3, question 1(c): In the stratosphere, nitrogen monoxide removes ozone molecules by the sequence of reactions below. NO(g) + O3(g) NO2(g) + O2(g) Reaction 1 NO2(g) + O(g) NO(g) +

  12. Q4(f)

    June 2023 · AS Paper 2

    2 marksOZ Kinetics
    The whole paper ↗
    June 2023 AS Paper 2, question 4(f): Draw a labelled Boltzmann distribution curve for a reaction. Mark the activation enthalpies when a catalyst is used and when it is not used. [2]

  13. Q32(c)(i)

    June 2022 · Paper 1

    1 markOZ Kinetics
    The whole paper ↗
    June 2022 Paper 1, question 32(c)(i): Explain what is meant by the term homogeneous as applied to a catalyst. [1]

  14. Q32(c)(iii)

    June 2022 · Paper 1

    1 markOZ Kinetics
    The whole paper ↗
    June 2022 Paper 1, question 32(c)(iii): Explain how a catalyst increases the rate of a reaction. [1]

  15. Q24(e)

    June 2022 · AS Paper 1

    2 marksOZ Kinetics
    The whole paper ↗
    June 2022 AS Paper 1, question 24(e): The students find data for repeating the experiment with the oil bath at 700 K. They notice that after 10 s the concentration of NO2 is 0.60 mol dm–3. Explain t

  16. Q2(b)(i)

    June 2022 · AS Paper 2

    1 markOZ Kinetics
    The whole paper ↗
    June 2022 AS Paper 2, question 2(b)(i): Explain how a catalyst increases the rate of a chemical reaction. [1]

  17. Q2(c)(ii)

    June 2022 · AS Paper 2

    1 markOZ Kinetics
    The whole paper ↗
    June 2022 AS Paper 2, question 2(c)(ii): What is acting as a catalyst in this catalytic cycle and what type of catalysis is involved? [1]

  18. Q4(c)

    November 2021 · AS Paper 2

    6 marksES EquilibriaOZ Kinetics
    The whole paper ↗
    November 2021 AS Paper 2, question 4(c): Methanol can be used as a fuel. It can be made industrially by the catalysed reaction between carbon monoxide and hydrogen as shown in Equation 4.1. CH3OH(g) ΔH

  19. Q4(d)(i)

    November 2021 · AS Paper 2

    3 marksOZ Kinetics
    The whole paper ↗
    November 2021 AS Paper 2, question 4(d)(i): Complete the enthalpy level diagram below to show the effect of a catalyst on the activation enthalpy for this exothermic reaction. You should draw and label en

  20. Q31(b)(ii)

    November 2020 · Paper 1

    1 markOZ Kinetics
    The whole paper ↗
    November 2020 Paper 1, question 31(b)(ii): How does the catalyst speed up the reaction? [1]
All 39 questions on Kinetics, as a list
  1. June 2025, Paper 1, Q31(c)(iii) (3 marks): Catalysis can be explained using a Boltzmann distribution. Use the diagram to explain how a catalyst speeds up a reaction. Label the diagram and write on the li
  2. June 2025, AS Paper 1, Q5 (1 mark): A student is measuring the effect of temperature on the rate of reaction of hydrochloric acid with calcium carbonate. What is a variable that must be controlled
  3. June 2025, AS Paper 2, Q1(b) (6 marks): Catalytic converters on cars use metals such as platinum as heterogeneous catalysts. Catalytic converters turn exhaust emissions such as carbon monoxide and nit
  4. June 2024, Paper 1, Q33(d)(ii) (2 marks): Draw an enthalpy profile diagram for the reaction in Equation 33.1 and label the catalysed and uncatalysed reactions. Show the reactants and products and the ac
  5. June 2024, AS Paper 1, Q24(a)(i) (1 mark): Fill in the missing value in the table. [1]
  6. June 2024, AS Paper 1, Q24(a)(ii) (3 marks): On the graph paper below, plot a graph of rate against volume of sodium thiosulfate, including the origin. Label the axes. Draw a line of best fit. [3]
  7. June 2024, AS Paper 1, Q24(a)(iii) (1 mark): Explain why ‘volume of sodium thiosulfate’ is proportional to ‘concentration of sodium thiosulfate’. [1]
  8. June 2024, AS Paper 1, Q24(a)(iv) (2 marks): The graph shows the relationship between rate and thiosulfate concentration for the reaction in Equation 24.1. Describe this relationship and explain it in term
  9. June 2024, AS Paper 1, Q24(b) (2 marks): The students repeat the experiment, varying the temperature. They find that the reaction gets faster as the temperature is increased. Complete and label the dia
  10. June 2023, Paper 3, Q1(b)(iii) (1 mark): The diagram below represents an energy profile for the catalysed reaction in Equation 1.1. enthalpy reactants products progress of reaction On the diagram: • In
  11. June 2023, Paper 3, Q1(c) (2 marks): In the stratosphere, nitrogen monoxide removes ozone molecules by the sequence of reactions below. NO(g) + O3(g) NO2(g) + O2(g) Reaction 1 NO2(g) + O(g) NO(g) +
  12. June 2023, AS Paper 2, Q4(f) (2 marks): Draw a labelled Boltzmann distribution curve for a reaction. Mark the activation enthalpies when a catalyst is used and when it is not used. [2]
  13. June 2022, Paper 1, Q32(c)(i) (1 mark): Explain what is meant by the term homogeneous as applied to a catalyst. [1]
  14. June 2022, Paper 1, Q32(c)(iii) (1 mark): Explain how a catalyst increases the rate of a reaction. [1]
  15. June 2022, AS Paper 1, Q24(e) (2 marks): The students find data for repeating the experiment with the oil bath at 700 K. They notice that after 10 s the concentration of NO2 is 0.60 mol dm–3. Explain t
  16. June 2022, AS Paper 2, Q2(b)(i) (1 mark): Explain how a catalyst increases the rate of a chemical reaction. [1]
  17. June 2022, AS Paper 2, Q2(c)(ii) (1 mark): What is acting as a catalyst in this catalytic cycle and what type of catalysis is involved? [1]
  18. November 2021, AS Paper 2, Q4(c) (6 marks): Methanol can be used as a fuel. It can be made industrially by the catalysed reaction between carbon monoxide and hydrogen as shown in Equation 4.1. CH3OH(g) ΔH
  19. November 2021, AS Paper 2, Q4(d)(i) (3 marks): Complete the enthalpy level diagram below to show the effect of a catalyst on the activation enthalpy for this exothermic reaction. You should draw and label en
  20. November 2020, Paper 1, Q31(b)(ii) (1 mark): How does the catalyst speed up the reaction? [1]
  21. November 2020, Paper 3, Q1(b) (6 marks): A student is investigating the properties of some s-block metals and their compounds. (b)* Group 2 carbonates react with hydrochloric acid as shown in equation
  22. June 2019, Paper 2, Q5(e)(ii) (1 mark): Suggest a reason for the involvement of the molecule M. [1]
  23. June 2019, AS Paper 1, Q21(c)(v) (2 marks): Ammonia is not often made at temperatures below 473 K. This is because the equilibrium is established too slowly at lower temperatures. Explain why the rate of
  24. June 2018, Paper 1, Q9 (1 mark): The enthalpy profiles for the reaction W + X Y + Z are shown below, with and without a catalyst. enthalpy W + X Y + Z progress of reaction Which statement is co
  25. June 2018, AS Paper 1, Q23(b)(i) (1 mark): State how catalysts work in terms of the activation enthalpy. [1]
  26. June 2018, AS Paper 1, Q24(b) (3 marks): The students look up some data for the experimentally measured rates of the reaction shown below. 2NO2 2NO + O2 Their data are shown in the table below. T / K R
  27. June 2018, AS Paper 1, Q24(c) (3 marks): Draw two Boltzmann distributions at different temperatures on the axes below. Use your diagram to explain why the rate of reaction increases with temperature. L
  28. June 2018, AS Paper 2, Q3(g)(iii) (1 mark): Explain how equations 3.1 and 3.2 show that Br could be a catalyst for the breakdown of ozone. [1]
  29. June 2017, Paper 1, Q31(d)(iii) (3 marks): Chlorine radicals in the stratosphere act as homogeneous catalysts in the breakdown of ozone. Give equations for the catalytic cycle. Use the equations to expla
  30. June 2017, AS Paper 1, Q20 (1 mark): Nitrogen monoxide, NO, reacts instantaneously in air to form NO2. What is an explanation for this? A NO is a radical taking part in a termination reaction. B th
  31. June 2017, AS Paper 2, Q1(b)(i) (1 mark): The student says that the same mass of each powdered transition metal oxide must be used in order to make valid comparisons. State and explain whether or not th
  32. June 2017, AS Paper 2, Q1(b)(ii) (1 mark): Identify two variables, apart from details of the transition metal oxide, that the student must control in this experiment. 1 2 [1]
  33. June 2017, AS Paper 2, Q1(c)(i) (1 mark): The first five results for manganese(IV) oxide have been plotted on page 5. Plot the remaining results and draw the line of best fit. [1] 5 70 60 50 40 volume o
  34. June 2017, AS Paper 2, Q1(c)(ii) (1 mark): Use the graph to explain which of the three catalysts is the most effective. [1]
  35. June 2017, AS Paper 2, Q1(c)(iii) (2 marks): The experiment is carried out at room temperature and pressure. Use the graph to calculate the average rate of formation of oxygen over the first 15 s using cop
  36. June 2016, AS Paper 1, Q20 (1 mark): Nitrogen and oxygen combine, as shown below. 2NO(g) ΔrH = +180 kJ mol−1 N2(g) + O2(g) Which statement is correct for this reaction? A The reaction is exothermic
  37. June 2016, AS Paper 1, Q24(b)(i) (3 marks): The students read the concentrations of ozone at certain times from the computer model. Concentration of ozone / molecules cm−3 Time / s 5.000 × 1012 0 4.989 ×
  38. June 2016, AS Paper 1, Q24(b)(ii) (1 mark): Use the graph to determine the concentration of ozone after 500 seconds. concentration = molecules cm−3 [1]
  39. June 2016, AS Paper 1, Q24(b)(iii) (1 mark): How does the rate of reaction vary with time? Explain your answer. [1]

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