From Mock A · Paper 2: Organic and Physical Chemistry
10.24 marks
50.0 cm³ of 1.00 mol dm⁻³ HCl was mixed with 50.0 cm³ of 1.00 mol dm⁻³ NaOH. The temperature rose by 6.8 K. Calculate the enthalpy of neutralisation (c = 4.18 J g⁻¹ K⁻¹; density 1.00 g cm⁻³).
From Mock A · Paper 2: Organic and Physical Chemistry
10.33 marks
Explain why the enthalpy of formation of methane cannot be measured directly and how it can be found.
From Mock A · Paper 2: Organic and Physical Chemistry
10.44 marks
Use mean bond enthalpies to calculate ΔH for C₂H₄ + H₂ → C₂H₆.
Bond
C=C
H–H
C–C
C–H
kJ mol⁻¹
612
436
348
412
From Mock A · Paper 3: Practical skills, all content and multiple choice
91 mark
Which is the standard enthalpy of combustion equation for ethanol?
From Mock B · Paper 1: Inorganic and Physical Chemistry
4.14 marks
In a calorimetry experiment, 0.0250 mol of acid reacted with alkali in 50.0 g of solution. The temperature rose by 6.5 K. Calculate the enthalpy change per mole of acid. (c = 4.18 J g⁻¹ K⁻¹)
From Mock B · Paper 1: Inorganic and Physical Chemistry
4.23 marks
Use mean bond enthalpies to calculate ΔH for CH₄ + 2O₂ → CO₂ + 2H₂O(g). (kJ mol⁻¹: C–H 413, O=O 498, C=O 805, O–H 464)
From Mock B · Paper 2: Organic and Physical Chemistry
15.23 marks
Burning 0.460 g of ethanol (Mr 46.0) heated 100 g of water by 25.0 K. Calculate the enthalpy of combustion of ethanol in kJ mol⁻¹. (c = 4.18 J g⁻¹ K⁻¹)
From Mock B · Paper 2: Organic and Physical Chemistry
15.33 marks
Explain why this value is much less exothermic than the data-book value of −1367 kJ mol⁻¹. Give three reasons.
From Mock B · Paper 3: Practical skills, all content and multiple choice
141 mark
Standard enthalpy of formation is defined for 1 mol of a compound formed from its elements under standard conditions. Which has ΔfH° = 0?
From Mock C · Paper 1: Inorganic and Physical Chemistry
4.13 marks
Use Hess's law to calculate ΔfH of propane from enthalpies of combustion (kJ mol⁻¹): C −394, H₂ −286, C₃H₈ −2220.
From Mock C · Paper 1: Inorganic and Physical Chemistry
4.22 marks
Define standard enthalpy of combustion.
From Mock C · Paper 2: Organic and Physical Chemistry
15.43 marks
Calculate ΔH for C₂H₄(g) + H₂O(g) → C₂H₅OH(g) using enthalpies of formation (kJ mol⁻¹): C₂H₄ +52, H₂O(g) −242, C₂H₅OH(g) −235.
From Mock C · Paper 3: Practical skills, all content and multiple choice
1.13 marks
Describe how to determine the enthalpy change of a reaction between zinc powder and copper(II) sulfate solution using a polystyrene cup.
From Mock C · Paper 3: Practical skills, all content and multiple choice
1.23 marks
Explain why the student plots a temperature–time graph and extrapolates the cooling line back to the time of mixing.
From Mock C · Paper 3: Practical skills, all content and multiple choice
1.34 marks
50.0 cm³ of 0.500 mol dm⁻³ CuSO₄ was used and the corrected ΔT was 25.2 K. Calculate ΔH for Zn + CuSO₄ → ZnSO₄ + Cu. (c = 4.18 J g⁻¹ K⁻¹; density 1.00 g cm⁻³)
From Mock C · Paper 3: Practical skills, all content and multiple choice
131 mark
Mean bond enthalpies are less accurate than Hess cycle values because
Score 0 / 45 · 0 of 16 marked
This paper is written by Plasmo in the style of the AQA A-Level Chemistry exam. It is not a past paper and is not produced or endorsed by the exam board.