Reversible reactions and equilibrium: past paper questions
Real questions on reversible reactions and equilibrium
The newest 20 of 63 written questions. Open one to see it on the real paper.
- 5070/21 · October/November 2025 · Q7b(ii)[2]
Describe and explain the effect of increasing the pressure on the position of equilibrium while keeping the temperature constant.
See it on the paper → - 5070/22 · October/November 2025 · Q5e[2]
The equation for the reversible reaction between carbon monoxide and nickel is shown. 4CO(g) + Ni(s) Ni(CO) 4 (g) The forward reaction is exothermic. The reversible reaction is allowed to reach equilibrium in a closed system. Predict and explain the effect of increasing the pressure on the position of equilibrium. The...
See it on the paper → - 5070/22 · May/June 2025 · Q6d(i)[2]
The temperature of the equilibrium mixture is increased. The pressure remains constant. State and explain what happens to the position of equilibrium. statement explanation
See it on the paper → - 5070/22 · May/June 2025 · Q6d(ii)[2]
The pressure of the equilibrium mixture is increased. The temperature remains constant. State and explain what happens to the position of equilibrium. statement explanation
See it on the paper → - 5070/21 · October/November 2024 · Q2e(i)[2]
Predict and explain what happens to the position of equilibrium when the pressure is decreased. The temperature remains the same. prediction explanation
See it on the paper → - 5070/21 · October/November 2024 · Q2e(ii)[2]
Describe and explain, by referring to the equation, how a sample of pure iron that is free from Fe(CO) 5 (l) is produced from the equilibrium mixture. This reaction can be used to produce pure iron.
See it on the paper → - 5070/21 · May/June 2024 · Q5a[2]
The temperature of the closed system is increased and the pressure is kept constant. Predict how the position of equilibrium of this reaction is affected. Explain your answer.
See it on the paper → - 5070/21 · May/June 2024 · Q5b[2]
The pressure of the closed system is decreased and the temperature is kept constant. Predict how the position of equilibrium of this reaction is affected. Explain your answer.
See it on the paper → - 5070/22 · May/June 2024 · Q5a[2]
The temperature of the closed system is decreased and the pressure is kept constant. Predict how the position of equilibrium of this reaction is affected. Explain your answer.
See it on the paper → - 5070/22 · May/June 2024 · Q5b[2]
The pressure of the closed system is increased and the temperature is kept constant. Predict how the position of equilibrium of this reaction is affected. Explain your answer.
See it on the paper → - 5070/21 · October/November 2023 · Q8a(i)[2]
Predict and explain the effect, if any, on the position of equilibrium when the pressure is decreased and the temperature remains constant.
See it on the paper → - 5070/21 · October/November 2023 · Q8a(ii)[1]
Predict and explain the effect, if any, on the position of equilibrium when the temperature is decreased and the pressure remains constant.
See it on the paper → - 5070/22 · October/November 2023 · Q8a(i)[2]
Predict and explain the effect, if any, on the position of equilibrium when the pressure is increased and the temperature remains constant.
See it on the paper → - 5070/22 · October/November 2023 · Q8a(ii)[1]
Predict and explain the effect, if any, on the position of equilibrium when the temperature is increased and the pressure remains constant.
See it on the paper → - 5070/21 · May/June 2023 · Q5a(i)[2]
State what is meant by the term equilibrium. Include ideas about rate of reaction and the concentrations of the reactant and products in your answer.
See it on the paper → - 5070/21 · May/June 2023 · Q5a(ii)[2]
Predict what happens to the position of equilibrium when the temperature is increased and the pressure remains constant. Explain your answer. prediction explanation
See it on the paper → - 5070/21 · May/June 2023 · Q5a(iii)[2]
Predict what happens to the position of equilibrium when the pressure is increased and the temperature remains constant. Explain your answer. prediction explanation
See it on the paper → - 5070/22 · May/June 2023 · Q5a(i)[1]
Explain why the reversible reaction must be in a closed system for an equilibrium mixture to be formed.
See it on the paper → - 5070/22 · May/June 2023 · Q5a(ii)[2]
Predict what happens to the position of equilibrium when the temperature is decreased and the pressure remains constant. Explain your answer. prediction explanation
See it on the paper → - 5070/22 · May/June 2023 · Q5a(iii)[2]
Predict what happens to the position of equilibrium when the pressure is decreased and the temperature remains constant. Explain your answer. prediction explanation
See it on the paper →
What examiners said
Better performing candidates explained the effect on the position of equilibrium. Favouring the left is insufficient for the equilibrium moving to the left. Common incorrect responses included: move to the right as there are moles of gas there; move to the right because it is exothermic and no change.
— Examiner report, October/November 2023, 5070/21 Q8(a)(i) (Cambridge)
Candidates found this difficult. Many thought the equilibrium moved to the left because there were either more or less molecules there. A small number omitted the question.
— Examiner report, October/November 2023, 5070/21 Q8(a)(ii) (Cambridge)
Some candidates confused arguments about rate and position of equilibrium and sometimes just focused on rate. Candidates needed to describe the correct movement of the position of equilibrium. In this case, the position moves to the side of the products. In this question there was no need to refer to moles of gas since all the substances in the equilibrium were gases but there had to be a statemen...
— Examiner report, October/November 2023, 5070/22 Q8(a)(i) (Cambridge)
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