plumiEntropy and entropy changes: OCR A‑Level Chemistry A questions
OCR A-Level Chemistry A past-paper questions on 5.2.2.1 Entropy and entropy changes, 2016–2025, with mark schemes and examiner’s reports where available.
All papers
All years
Q17(a)(iii)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ17(a)(iv)
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFYour answerQ18(c)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFYour answerQ17(c)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ5(d)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ19(a)(ii)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ5(b)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFYour answerQ17(d)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ17(d)(ii)
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDF
All 12 questions on Entropy and entropy changes, as a list
- June 2025, Paper 1, Q17(a)(iii) (2 marks): Explain why the standard entropy of CO2 is greater than the standard entropy of Fe2O3. [2]
- June 2025, Paper 1, Q17(a)(iv) (2 marks): The standard entropy change, ΔSɵ, for the forward reaction in Equilibrium 17.1 has a value of +15 J K–1 mol–1. Use data from the table to calculate the standard
- June 2023, Paper 1, Q9 (1 mark): The table below shows standard entropies, Sө. 9 Substance SO2(g) O2(g) SO3(l) Sө/J K–1 mol–1 248 204 96 What is the standard entropy change, ∆Sө, in J K mol–1,
- June 2023, Paper 1, Q18(c)(i) (1 mark): Predict the sign of the entropy change, ∆S, for Reaction 2. Explain your reasoning. [1]
- June 2022, Paper 1, Q10 (1 mark): For the condensation of ammonia gas, what are the signs of ∆H and ∆S? A ∆H –ve ∆S –ve B ∆H –ve ∆S +ve C ∆H +ve ∆S +ve D ∆H +ve ∆S –ve Your answer [1]
- June 2022, Paper 1, Q17(c)(i) (1 mark): Explain the term entropy. [1]
- November 2020, Paper 3, Q5(d) (2 marks): Explain how ∆S could be calculated from a graph of ln Kp against 1 T . [2]
- June 2019, Paper 1, Q19(a)(ii) (4 marks): Some standard entropy values are given below. Substance H2S(g) O2(g) SO2(g) H2O(l) Sө / J K−1 mol−1 206 205 248 70 Using calculations, explain whether Reaction
- June 2019, Paper 3, Q5(b) (4 marks): The standard enthalpy change of reaction, ∆rH o , and the standard free energy change, ∆G o , for converting anhydrous sodium thiosulfate to hydrated sodium thi
- June 2018, Paper 1, Q11 (1 mark): The table below shows standard entropies, Sө. Substance CO(g) H2(g) CH3OH(l) Sө / J mol–1 K–1 197.6 130.6 239.7 What is the entropy change, ∆Sө, in J mol–1 K–1,
- June 2017, Paper 1, Q17(d)(i) (2 marks): The reaction of aqueous barium nitrate with aqueous sodium sulfate. Full equation with state symbols Explanation of entropy change [2]
- June 2017, Paper 1, Q17(d)(ii) (2 marks): The change that accompanies the standard enthalpy change of atomisation of iodine. Equation with state symbols Explanation of entropy change [2]
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.