plumiPartial pressures and equilibrium quantities: OCR A‑Level Chemistry A questions
OCR A-Level Chemistry A past-paper questions on 5.1.2.1 Partial pressures and equilibrium quantities, 2016–2025, with mark schemes and examiner’s reports where available.
All papers
All years
Q17(c)(ii)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ18(a)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ19(a)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ20(c)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ1(a)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ19(b)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ19(b)(ii)
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFQ1(c)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFYour answerQ18(b)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ5(b)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ5(b)(v)
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFYour answerQ20(b)(ii)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ3(c)(ii)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDF
All 15 questions on Partial pressures and equilibrium quantities, as a list
- June 2025, Paper 1, Q17(c)(ii) (3 marks): 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
- June 2024, Paper 1, Q18(a)(i) (5 marks): 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 0.9
- June 2023, Paper 1, Q19(a)(i) (5 marks): 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 o
- November 2021, Paper 1, Q20(c)(i) (4 marks): Calculate Kp, in MPa–1, for Equilibrium 20.1. Give your answer to 3 significant figures. Kp = MPa–1 [4]
- November 2021, Paper 3, Q1(a) (2 marks): 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]
- June 2019, Paper 1, Q19(b)(i) (2 marks): Write an expression for Kp for Equilibrium 1. Include the units. units = [2]
- June 2019, Paper 1, Q19(b)(ii) (5 marks): Determine the value of Kp for Equilibrium 1 at 1000 K. Show all your working. Give your answer to 3 significant figures. Kp = [5]
- June 2019, Paper 3, Q1(c) (1 mark): 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 [
- June 2018, Paper 1, Q9 (1 mark): 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
- June 2018, Paper 1, Q18(b) (4 marks): 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
- June 2018, Paper 3, Q5(b)(i) (1 mark): Which technique could be used to determine the equilibrium amount of succinic acid? [1]
- June 2018, Paper 3, Q5(b)(v) (3 marks): Calculate the value of Kc for this reaction. Show your working. Kc = [3]
- June 2017, Paper 1, Q13 (1 mark): 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
- June 2017, Paper 1, Q20(b)(ii) (4 marks): 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. Sho
- June 2017, Paper 3, Q3(c)(ii) (3 marks): Peroxyethanoic acid can be prepared by reacting hydrogen peroxide with ethanoic acid. This is a heterogeneous equilibrium. CH3COOOH(aq) + H2O(l) Kc = 0.37 dm3 m
Questions, mark schemes and examiner’s reports are © OCR, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? OCR A-Level Chemistry A past papers, or our free OCR-style practice pack.
The Plumi iPad app also offers exam-style questions with AI feedback on your handwritten working.