plumiBond enthalpies: Edexcel International A Level Chemistry questions
Every Edexcel International A Level Chemistry exam question on Bond enthalpies (specification points 6.9–6.11), 2019–2025, with its mark scheme and examiner’s report.
Paper
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Exam
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Calculations
Q2(a)
The whole paper ↗Your answerQ16(a)(ii)
The whole paper ↗Q21(a)
The whole paper ↗Q21(c)
The whole paper ↗Q2(c)
The whole paper ↗Your answer- Your answer
Q15(c)(ii)
The whole paper ↗- Your answer
Q24(a)(i)
The whole paper ↗Q24(a)(ii)
The whole paper ↗Q19(a)(ii)
The whole paper ↗- Your answer
Q20(a)(i)
The whole paper ↗Q20(a)(ii)
The whole paper ↗- Your answer
- Your answer
Q18(c)
The whole paper ↗- Your answer
Q21(a)(ii)
The whole paper ↗Q19(b)(i)
The whole paper ↗
All 24 questions on Bond enthalpies, as a list
- June 2025, AS Unit 2, Q2(a) (1 mark): Methane burns to produce carbon dioxide and water vapour. CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) ΔH = –810 kJ mol–1 Some bond enthalpy data are shown. Bond enthalpy
- June 2025, Unit 5, Q16(a)(ii) (2 marks): Calculate the mean carbon-carbon bond enthalpy in benzene, using your completed cycle and the data shown. (2) C6H6(l) ΔfH = +49.0 kJ mol C(s) → C(g) ΔatH = +715
- January 2025, AS Unit 2, Q21(a) (3 marks): Calculate the enthalpy change per mole of methanol produced, using the bond enthalpies shown. H H H ⇋ + 2 2 H C H O O C H H O H Bond Enthalpy / kJ mol–1 O O 498
- January 2025, AS Unit 2, Q21(c) (2 marks): The standard enthalpy change of reaction to form methanol from methane calculated in part (a) is less accurate than the value given in the Hess cycle in part (b
- October 2024, AS Unit 2, Q2(c) (1 mark): Some bond enthalpies are shown. Bond enthalpy / kJ mol–1 Bond H H 436 C O 1077 O H 464 What is the bond enthalpy, in kJ mol–1, of the C H bond? (1) A 198 B 313
- June 2024, AS Unit 2, Q3 (1 mark): Which equation represents the reaction for which the enthalpy change, ΔrH, is the mean bond enthalpy of the C Cl bond in CCl4? A CCl4(g) → C(g) + 4Cl(g) B ¼CCl4
- June 2024, Unit 4, Q15(c)(ii) (1 mark): State why the entropy change of the surroundings for Reaction 2 is highly positive, in terms of the bond strengths of the reactants and products. (1)
- June 2024 (R), AS Unit 2, Q4 (1 mark): Nitrogen reacts with hydrogen to form ammonia. ½N2(g) + 1½H2(g) NH3(g) ∆fH = –46 kJ mol–1 Bond Bond enthalpy / kJ mol–1 H H 436 N N 945 What is the bond entha
- January 2024, AS Unit 2, Q24(a)(i) (3 marks): Calculate the mean bond enthalpy, in kJ mol–1, for a single S F bond. (3)
- January 2024, AS Unit 2, Q24(a)(ii) (2 marks): Give two reasons why your answer to (a)(i) is unlikely to accurately represent the true S F bond enthalpy in SF6 . (2)
- January 2024, Unit 4, Q19(a)(ii) (2 marks): The standard enthalpy change, ΔrH d, for this reaction is close to, but not exactly zero. Explain this statement by considering the type and number of bonds bei
- October 2023, AS Unit 2, Q1 (1 mark): The mean C–F bond enthalpy is +485 kJ mol–1. Which process has an enthalpy change of +1940 kJ mol–1? A C(g) + 4F(g) → CF4(g) B C(s) + 2F2(g) → CF4(g) C CF4(g) →
- June 2023, AS Unit 2, Q20(a)(i) (4 marks): Use mean bond enthalpies to calculate a value for the enthalpy change of combustion of octane. (4) Bond C C C H O H O O C O Mean bond enthalpy 347 413 464 498 8
- June 2023, AS Unit 2, Q20(a)(ii) (2 marks): The standard enthalpy change of combustion, ΔcH , of octane is –5470 kJ mol–1. Give two reasons why this value, measured under standard conditions, is different
- January 2023, AS Unit 2, Q3 (1 mark): The enthalpy change of reaction, ΔrH , for the equation shown can be calculated using bond enthalpy data. ½H2(g) + ½Cl2(g) → HCl(g) Bond enthalpy / kJ mol–1 Bon
- October 2022, AS Unit 2, Q1 (1 mark): Hydrogen reacts with oxygen to form steam. H2(g) + ½O2(g) → H2O(g) ∆H = −242 kJ mol−1 Bond enthalpy / kJ mol−1 Bond H H 436 O O 498 What is the bond enthalpy of
- June 2022, AS Unit 2, Q18(c) (3 marks): The enthalpy changes for the conversion of four compounds in the gas phase into their constituent atoms are shown. H2O(g) → 2H(g) + O(g) ΔrH = +928 kJ mol−1 CH4
- January 2022, AS Unit 2, Q4 (1 mark): The equation for the complete combustion of methanal is shown. O O → O ΔH = –591 kJ mol−1 C + O C O + O H H H H Some bond enthalpy data are shown. Bond enthalpy
- January 2022, Unit 4, Q21(a)(ii) (2 marks): The enthalpy change for this reaction is small. Explain, by reference to the type and number of bonds being broken and made, how this might have been predicted.
- October 2021, AS Unit 2, Q19(b)(i) (2 marks): Give the meaning of the term ‘mean bond enthalpy’. (2)
- October 2021, AS Unit 2, Q19(b)(ii) (3 marks): Calculate a value for the enthalpy change of combustion of methanol, using the information in the table and the equation shown. (3) CH3OH + 1½O2 ® CO2 + 2H2O C–
- October 2020, AS Unit 2, Q1 (1 mark): The bond enthalpy for the Cl Cl bond is +243.0 kJ mol–1. What is the enthalpy change of atomisation of chlorine in kJ mol–1? A +243.0 B –243.0 C +121.5 D –121.5
- January 2020, AS Unit 2, Q3 (1 mark): Nitrogen reacts with hydrogen to form ammonia. N2(g) + 3H2(g) U 2NH3(g) ǻrH = −92 kJ mol−1 Bond energy / kJ mol−1 Bond N N 945 H H 436 What is the mean bond ene
- June 2019, AS Unit 2, Q10 (1 mark): Chlorine reacts with ethane to form chloroethane and hydrogen chloride. Cl2 + C2H6 → C2H5Cl + HCl Bond enthalpy Bond / kJ mol–1 C—Cl 346 C—H 413 Cl—Cl 243 H—Cl
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