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Equilibrium constants: Eduqas A‑Level Chemistry questions

Every Eduqas A-Level Chemistry exam question on PI5.1 Equilibrium constants, 2016–2025, with its mark scheme and examiner’s report.

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1,513 questions

  1. Q13(a)

    June 2025 · Component 1

    4 marksPI5.1 Equilibrium constants
    The whole paper ↗
    June 2025 Component 1, question 13(a): Addition of iodide ions causes the following equilibrium to be established. I2(aq) + I–(aq) I3 –(aq) A solid sample of 0.100 g of potassium iodide is added to 1

  2. Q13(a)

    June 2024 · Component 1

    1 markPI5.1 Equilibrium constants
    The whole paper ↗
    June 2024 Component 1, question 13(a): Use the words high or low to complete the sentences below. [1] The concentration of N2O in an equilibrium mixture formed for equilibrium 1 is The concentration

  3. Q13(b)

    June 2024 · Component 1

    2 marksPI5.1 Equilibrium constants
    The whole paper ↗
    June 2024 Component 1, question 13(b): Write an expression for Kp for equilibrium 2. Give its unit. [2] Unit

  4. Q13(c)

    June 2024 · Component 1

    4 marksPI5.1 Equilibrium constants
    The whole paper ↗
    June 2024 Component 1, question 13(c): A different equilibrium involving N2O is shown below. 3NO(g) N2O(g) + NO2(g) A sample of NO at a total pressure of 1 atm was allowed to reach equilibrium and th

  5. Q4

    Autumn 2021 · Component 1

    3 marksPI5.1 Equilibrium constants
    The whole paper ↗
    Autumn 2021 Component 1, question 4: In the gas phase phosphorus(V) chloride dissociates according to the equation below. PCl5(g) PCl3(g) + Cl2(g) A sample of pure PCl5 is allowed to dissociate in

  6. Q13(a)(iv)

    June 2019 · Component 1

    2 marksPI5.1 Equilibrium constants
    The whole paper ↗
    June 2019 Component 1, question 13(a)(iv): State the effect (if any) of increasing temperature on the value of Kc. Give a reason for your answer. [2]

  7. Q13(a)(v)

    June 2019 · Component 1

    3 marksPI5.1 Equilibrium constants
    The whole paper ↗
    June 2019 Component 1, question 13(a)(v): A mixture of nitrogen and hydrogen has an initial concentration of 0.020 mol dm−3 of each gas. The mixture is allowed to come to equilibrium in a fixed volume.

  8. Q5(a)(i)

    June 2018 · Component 3

    1 markPI5.1 Equilibrium constants
    The whole paper ↗
    June 2018 Component 3, question 5(a)(i): The six steps in the calculation to find the value for the equilibrium constant K are shown in a random order in the table below. Number these steps in the corr

  9. Q5(a)(ii)

    June 2018 · Component 3

    5 marksPI5.1 Equilibrium constants
    The whole paper ↗
    June 2018 Component 3, question 5(a)(ii): Calculate the value of K. [5] K =

  10. Q10(c)(iii)

    June 2017 · Component 1

    6 marksPI5.1 Equilibrium constants
    The whole paper ↗
    June 2017 Component 1, question 10(c)(iii): I. Explain why the percentage of carbon monoxide in the equilibrium mixture in the water gas shift reaction (equation 2) is lower at low temperature than at hig
All 10 questions on Equilibrium constants, as a list
  1. June 2025, Component 1, Q13(a) (4 marks): Addition of iodide ions causes the following equilibrium to be established. I2(aq) + I–(aq) I3 –(aq) A solid sample of 0.100 g of potassium iodide is added to 1
  2. June 2024, Component 1, Q13(a) (1 mark): Use the words high or low to complete the sentences below. [1] The concentration of N2O in an equilibrium mixture formed for equilibrium 1 is The concentration
  3. June 2024, Component 1, Q13(b) (2 marks): Write an expression for Kp for equilibrium 2. Give its unit. [2] Unit
  4. June 2024, Component 1, Q13(c) (4 marks): A different equilibrium involving N2O is shown below. 3NO(g) N2O(g) + NO2(g) A sample of NO at a total pressure of 1 atm was allowed to reach equilibrium and th
  5. Autumn 2021, Component 1, Q4 (3 marks): In the gas phase phosphorus(V) chloride dissociates according to the equation below. PCl5(g) PCl3(g) + Cl2(g) A sample of pure PCl5 is allowed to dissociate in
  6. June 2019, Component 1, Q13(a)(iv) (2 marks): State the effect (if any) of increasing temperature on the value of Kc. Give a reason for your answer. [2]
  7. June 2019, Component 1, Q13(a)(v) (3 marks): A mixture of nitrogen and hydrogen has an initial concentration of 0.020 mol dm−3 of each gas. The mixture is allowed to come to equilibrium in a fixed volume.
  8. June 2018, Component 3, Q5(a)(i) (1 mark): The six steps in the calculation to find the value for the equilibrium constant K are shown in a random order in the table below. Number these steps in the corr
  9. June 2018, Component 3, Q5(a)(ii) (5 marks): Calculate the value of K. [5] K =
  10. June 2017, Component 1, Q10(c)(iii) (6 marks): I. Explain why the percentage of carbon monoxide in the equilibrium mixture in the water gas shift reaction (equation 2) is lower at low temperature than at hig

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