Question
WJEC Unit 2 — required practical
A student measured the enthalpy change of neutralisation between HCl and NaOH.
- 25.0 cm³ of 1.0 mol/dm³ HCl and 25.0 cm³ of 1.0 mol/dm³ NaOH were mixed in a polystyrene cup.
- Initial temperature: 21.5 °C; Maximum temperature: 28.2 °C
- Specific heat capacity of solution: 4.18 J g⁻¹ °C⁻¹; assume density of solution = 1.0 g/cm³.
(a) Calculate the mass of solution in the cup. (1 mark) (b) Calculate q, the energy released in the reaction. (3 marks) (c) Calculate the moles of water produced. (1 mark) (d) Calculate ΔH (kJ/mol), and explain the sign. (3 marks)
8 marks · take your time before peeking.
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