Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Reversible Reactions and Equilibria
144 practice questions
Topics covered
- Reversibility and dynamic equilibria19 practice questions
- Reversible reactions in a sealed container18 practice questions
- The position of equilibrium20 practice questions
- Changing the pressure19 practice questions
- Changing the temperature19 practice questions
- Adding a catalyst19 practice questions
- The effect of concentration19 practice questions
Practice questions
81–90 of 144
Question 81
3 marks · Easy
Answer and see the solution →Equilibrium composition for a reaction at two temperatures. Temperature (°C) % S at equilibrium % T at equilibrium 350 30 70 600 55 45 (a)[1 mark]At which temperature is there more S at equilibrium?
(b)[1 mark]Describe how increasing temperature affects the position of equilibrium in this reaction.
(c)[1 mark]Suggest whether the forward reaction is likely to be exothermic or endothermic. Explain your answer.
Question 82
1 mark · Easy
Answer and see the solution →In a reversible reaction where the forward reaction is endothermic, what effect does decreasing the temperature have on the direction of equilibrium?
Question 83
3 marks · Easy
Answer and see the solution →(a)[1 mark]Consider a reversible reaction: Explain whether the forward reaction is exothermic or endothermic.
(b)[2 marks]If the temperature is increased, which direction of reaction will be favoured? Explain your answer.
Question 84
2 marks · Easy
Answer and see the solution →For the reaction below, predict which direction the position of equilibrium will shift if the temperature is decreased. , \( \Delta H = +110\ \text{kJ/mol} \ )
Question 85
2 marks · Normal
Answer and see the solution →State how changing the temperature affects the position of equilibrium in a reversible reaction.
Question 86
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 87
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 88
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 89
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 90
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.