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
31–40 of 63 · Normal
Question 31
1 mark · Normal
Answer and check →Consider the following equilibrium:
What will happen to the position of equilibrium if the pressure is increased?
- A.It shifts to the left (towards \ce{F2})
- B.It shifts to the right (towards \ce{F})
- C.No effect
- D.It shifts to both sides equally
Question 32
2 marks · Normal
Answer and see the solution →For equilibria involving only solids and liquids, changing the pressure has very little effect. Give two reasons why.
Question 33
4 marks · Normal
Answer and see the solution →Carbon monoxide and hydrogen react according to the following equation:
(a)[1 mark]How many moles of gaseous molecules are there on each side of the equation?
(b)[3 marks]If the pressure is increased, what happens to the position of equilibrium? Explain your answer.
Question 34
3 marks · Normal
Answer and see the solution →The following reaction is allowed to reach equilibrium in a sealed container:
The number of gaseous molecules on each side of the equation is different.
Explain, with calculations, why increasing the pressure will affect this equilibrium, and state which side the equilibrium will shift towards. Use the number of moles of gas in your answer.
Question 35
2 marks · Normal
Answer and see the solution →State how changing the temperature affects the position of equilibrium in a reversible reaction.
Question 36
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 37
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 38
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 39
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 40
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.