Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Changing the temperature
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State how changing the temperature affects the position of equilibrium in a reversible reaction.
Question 2
4 marks · Normal
Answer and see the solution →For the following reversible reaction, answer the questions below:
(a)[1 mark]Is the forward reaction exothermic or endothermic? Explain your reasoning.
(b)[2 marks]What will happen to the position of equilibrium if the temperature is increased? Explain your answer.
(c)[1 mark]State whether more SO3 or more SO2 will be present at equilibrium if the temperature is decreased. Give a reason for your answer.
Question 3
3 marks · Normal
Answer and see the solution →A reversible reaction is shown below.
Calculate the enthalpy change (ΔH) for the reverse reaction. State whether the reverse reaction is exothermic or endothermic.
Question 4
3 marks · Normal
Answer and see the solution →The reaction below reaches equilibrium at a certain temperature:
Explain what will happen to the position of equilibrium if you decrease the temperature. Refer to the direction of the equilibrium shift.
Question 5
4 marks · Normal
Answer and see the solution →The table below shows the percentage of X and Y at equilibrium for a reversible reaction at two temperatures.
Temperature (°C) % X at equilibrium % Y at equilibrium 350 30 70 150 65 35 (a)[1 mark]Describe how the percentage of X changes as temperature decreases.
(b)[2 marks]Which direction of reaction is favoured at lower temperature? Explain your answer using the data.
(c)[1 mark]State whether the formation of X from Y is likely exothermic or endothermic. Give a reason.
Question 6
1 mark · Normal
Answer and check →Which statement about ΔH for a reversible reaction is correct?
- A.ΔH always refers to the forward reaction.
- B.ΔH is positive for all exothermic reactions.
- C.ΔH is the same for both directions of the reaction.
- D.ΔH is only given for endothermic reactions.
Question 7
2 marks · Normal
Answer and see the solution →Explain what happens to the position of equilibrium when temperature is increased in a reversible reaction.
Question 8
4 marks · Normal
Answer and see the solution →The equation below shows a reversible reaction.
(a)[1 mark]Is the forward reaction exothermic or endothermic? Explain your answer.
(b)[2 marks]Predict what happens to the position of equilibrium if the temperature is decreased. Explain your answer.
(c)[1 mark]Which direction (left or right) is favoured when temperature is increased? Explain.