plumiApplications of Hess’s law: AQA A‑Level Chemistry questions
AQA A-Level Chemistry past-paper questions on 3.1.4.3 Applications of Hess’s law, 2008–2025, with mark schemes and examiner’s reports where available.
Paper
All papers
Exam
All years
Calculations
Loading the question…
Open the full PDFQ08.2
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ08.3
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFLoading the question…
Open the full PDFQ08.7
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ04.1
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFQ01.2
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFLoading the question…
Open the full PDFYour answerQ03.3
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ07.5
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFLoading the question…
Open the full PDFQ01.2
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ02.2
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ02.3
The whole paper ↗Loading the start of the question…
Loading the question…
Open the full PDFQ6(a)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ2(b)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDFQ3(a)(i)
The whole paper ↗
Loading the start of the question…
Loading the question…
Open the full PDF
All 44 questions on Applications of Hess’s law, as a list
- June 2025, AS Paper 2, Q18 (1 mark): The standard enthalpies of combustion for carbon, hydrogen and benzene (C6H6) are –394, –286 and –3273 kJ mol–1 respectively. What is the standard enthalpy of f
- June 2024, AS Paper 1, Q08.2 (2 marks): Silver nitrate(V) is formed when silver nitrate(III) undergoes thermal decomposition. 2 AgNO2(s) ⟶ Ag(s) + AgNO3(s) + NO(g) ΔH = +56.2 kJ mol–1 The standard ent
- June 2024, AS Paper 1, Q08.3 (1 mark): Suggest why the enthalpy change for the thermal decomposition of solid silver nitrate(III) is difficult to determine experimentally. [1 mark]
- June 2024, AS Paper 2, Q19 (1 mark): What is the enthalpy of combustion, in kJ mol–1, of propane? [1 mark] A −211.7 B −419.7 C −2220 D −2878
- June 2024, AS Paper 2, Q20 (1 mark): What is the enthalpy change, in kJ mol–1, when butane reacts to form propane, hydrogen and carbon? [1 mark] A +21.2 B +17.5 C −17.5 D −21.2
- June 2023, Paper 2, Q08.7 (2 marks): The carbon dioxide produced from fermentation can be reacted with steam to make more ethanol. The equation for this reaction is 2 CO2(g) + 3 H2O(g) → C2H5OH(g)
- November 2021, Paper 2, Q04.1 (3 marks): Use Figure 3 and the data shown in Table 1 to calculate ΔH2 [3 marks] Table 1 ΔH / kJ mol–1 Enthalpy of atomisation for carbon +715 Enthalpy of atomisation for
- November 2020, AS Paper 1, Q20 (1 mark): Two reactions of iron with oxygen are shown. Fe(s) + 1 2 O2(g) → FeO(s) ΔH = – 272 kJ mol–1 2 Fe(s) + 3 2 O2(g) → Fe2O3(s) ΔH = – 822 kJ mol–1 What is the entha
- November 2020, AS Paper 2, Q01.2 (3 marks): The equation for a reaction used to manufacture 1-chloropropane is 3 CH3CH2CH2OH(l) + PCl3(l) → 3 CH3CH2CH2Cl(l) + H3PO3(s) The enthalpy change for this reactio
- November 2020, AS Paper 2, Q21 (1 mark): Some enthalpy change data are shown. C(s) + 2 H2(g) → CH4(g) ΔH = –75 kJ mol–1 H2(g) → 2 H(g) ΔH = +436 kJ mol–1 What is the enthalpy change, in kJ mol–1, for t
- June 2019, Paper 3, Q08 (1 mark): Nitrogen dioxide is produced from ammonia and air as shown in these equations 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g) ΔH = –909 kJ mol–1 2 NO(g) + O2(g) → 2 NO2
- June 2019, AS Paper 2, Q03.3 (3 marks): Table 2 gives some values of standard enthalpies of combustion (∆cHo). Table 2 Substance C(s) H2(g) C6H12(l) Standard enthalpy of combustion, ∆cHo / kJ mol–1 –3
- June 2018, AS Paper 1, Q07.5 (2 marks): Potassium chlorate(VII), KClO4, is used in fireworks. When potassium chlorate(VII) decomposes, it produces potassium chloride and oxygen. Give an equation for t
- June 2018, AS Paper 2, Q20 (1 mark): What is the enthalpy of formation of buta-1,3-diene, C4H6(g)? Substance Enthalpy of combustion / kJ mol–1 C4H6(g) –2546 C(s) –394 H2(g) –286 [1 mark] A +112 kJ
- June 2017, Paper 3, Q01.2 (2 marks): Some enthalpies of solution are shown in Table 1. Table 1 Salt Enthalpy of solution / kJ mol−1 MgCl2(s) −155 MgCl2.4H2O(s) −39 Calculate the enthalpy change for
- June 2017, AS Paper 1, Q02.2 (3 marks): Table 2 contains some standard enthalpy of formation data. Table 2 CO(g) Fe2O3(s) ΔfH o / kJ mol−1 −111 −822 Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g) ΔH = −19 kJ mo
- June 2017, AS Paper 1, Q02.3 (3 marks): Some enthalpy data are given in Table 3. Table 3 Process ΔH / kJ mol−1 N2(g) + 3H2(g) → 2NH3(g) −92 N2(g) → 2N(g) +944 H2(g) → 2H(g) +436 Use the data from Tabl
- June 2016, CHEM5 (old spec), Q6(a) (2 marks): Use data from Table 3 to calculate the standard enthalpy change for this reaction. [2 marks]
- June 2016, CHEM2 (old spec), Q2(b) (3 marks): The equation corresponding to the enthalpy of formation of propan-1-ol is shown. 3C(s) + 4H2(g) + –O2(g) CH3CH2CH2OH(l) Table 1 contains some standard enthalpy
- June 2015, CHEM5 (old spec), Q3(a)(i) (3 marks): Use data from Table 4 to calculate the enthalpy change, ΔH, for the reaction of steam with methane. [3 marks]
- June 2015, CHEM2 (old spec), Q9(a) (5 marks): Table 3 shows some standard enthalpy of formation data. Table 3 In the oldest method of extraction of vanadium, V2O5 is reacted with calcium at a high temperatu
- June 2014, CHEM2 (old spec), Q3(c)(i) (3 marks): Use the standard enthalpies of formation in Table 1 and the equation given below Table 1 to calculate a value for the standard enthalpy change for this reaction
- June 2013, CHEM2 (old spec), Q11(a) (5 marks): Strontium is extracted from strontium oxide (SrO) by heating a mixture of powdered strontium oxide and powdered aluminium. Consider these standard enthalpies of
- January 2013, CHEM2 (old spec), Q3(a)(i) (3 marks): Use the standard enthalpy of formation data from the table and the equation for the extraction of manganese to calculate a value for the standard enthalpy chang
- January 2013, CHEM2 (old spec), Q4(a) (1 mark): State Hess’s Law. (1 mark)
- January 2013, CHEM2 (old spec), Q4(b) (1 mark): Write a mathematical expression to show how ΔHexp, ΔH1 and ΔH2 are related to each other by Hess’s Law. (1 mark)
- January 2013, CHEM2 (old spec), Q4(c) (1 mark): Use the mathematical expression that you have written in part (b), and the data book values for the two enthalpy changes ΔH1 and ΔH2 shown, to calculate a value
- January 2013, CHEM2 (old spec), Q4(e) (1 mark): Suggest one reason why the value for ΔHexp cannot be measured directly. (1 mark)
- June 2012, CHEM5 (old spec), Q4(a) (2 marks): Calculate the enthalpy change for this reaction.
- June 2012, CHEM2 (old spec), Q2(a)(i) (3 marks): Use these standard enthalpies of formation to calculate a value for the standard enthalpy change of this synthesis. CO2(g) + 3H2(g) CH3OH(g) + H2O(g)
- January 2012, CHEM2 (old spec), Q4(b)(i) (1 mark): Suggest why it is not possible to measure the enthalpy change directly for the following combustion reaction. C(s,graphite) + –O2(g) CO(g) (1 mark) 1 2
- January 2012, CHEM2 (old spec), Q4(b)(ii) (1 mark): State Hess’s Law. (1 mark)
- January 2012, CHEM2 (old spec), Q4(c) (3 marks): Use the standard enthalpies of formation in the table below and the equation to calculate a value for the standard enthalpy change for the extraction of iron us
- June 2011, CHEM2 (old spec), Q2(c) (1 mark): State Hess’s Law. (1 mark)
- June 2011, CHEM2 (old spec), Q2(e)(ii) (3 marks): Use data from the table to calculate a value for the standard enthalpy change of the following reaction. TiCl4(g) + 4Na(I) 4NaCl(s) + Ti(s)
- January 2011, CHEM2 (old spec), Q9(c)(ii) (3 marks): Use the standard enthalpy of formation data from the table and the equation for the combustion of butan-1-ol to calculate a value for the standard enthalpy of c
- June 2010, CHEM5 (old spec), Q6(a) (3 marks): Calculate the standard enthalpy change for this reaction.
- June 2010, CHEM2 (old spec), Q4(c)(i) (3 marks): Use the standard enthalpies of formation in the table below to calculate a value for the standard enthalpy change of this reaction.
- January 2010, CHEM2 (old spec), Q2(b) (1 mark): State Hess’s Law. (1 mark)
- January 2010, CHEM2 (old spec), Q2(c) (3 marks): Consider the following table of data and the scheme of reactions. Use the data in the table, the scheme of reactions and Hess’s Law to calculate a value for ∆Hr
- June 2009, CHEM2 (old spec), Q2(a)(iii) (3 marks): 2 (a) (iii) Use the data to calculate the standard enthalpy change for the reaction shown by the equation above. (3 marks)
- June 2008, CHM2 (2008 spec), Q2(b) (1 mark): 2 (b) State Hess’s Law. (1 mark)
- June 2008, CHM2 (2008 spec), Q2(c) (3 marks): 2 (c) The equation below shows the formation of buta-1,3-diene, C4H6 4C(s) + 3H2(g) →C4H6(g) Use the following data to calculate the standard enthalpy of format
- January 2008, CHM2 (2008 spec), Q3(c) (3 marks): (c) The following table gives some standard enthalpies of formation. Use these data to calculate a value for the enthalpy of combustion, ∆Hc , of propan-1-ol, C
Questions, mark schemes and examiner’s reports are © AQA, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? AQA A-Level Chemistry past papers.
The Plumi iPad app also offers exam-style questions with AI feedback on your handwritten working.