Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Measuring enthalpy changes of reactions
19 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →A student wants to measure the enthalpy change for the reaction between hydrochloric acid and sodium carbonate solution using a polystyrene cup calorimeter.
State two steps the student should follow to ensure the experiment produces reliable results.
Question 2
5 marks · Hard
Answer and see the solution →Copper(II) sulfate crystals dissolve in water in a polystyrene cup calorimeter. A student wants to determine the enthalpy change of the process.
(a)[2 marks]State two measurements the student must take to calculate the enthalpy change. (2 marks)
(b)[2 marks]The student dissolves 10.0 g of copper(II) sulfate ( ) in 50.0 g of water. The temperature rises by 7.4 °C. Calculate the heat absorbed or released by the water. (Specific heat capacity of water = 4.2 J/g°C) Give your answer to three significant figures. (2 marks)
(c)[1 mark]Explain whether the dissolving of copper(II) sulfate in water is exothermic or endothermic, based on your calculation. (1 mark)
Question 3
2 marks · Hard
Answer and see the solution →In a calorimetry experiment, a student measures a temperature decrease during the reaction.
Explain what this temperature change tells you about the type of reaction and the direction of energy transfer.