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
51–57 of 57 · Easy
Question 51
3 marks · Easy
Answer and see the solution →The equilibrium below is set up in a sealed vessel:
The graph shows how the concentration of AB(g) changes after some B2(g) is added:
Concentration of AB(g) vs. time after B2(g) is added. (a)[1 mark]Describe what happens to [AB] after B2(g) is added.
(b)[2 marks]Predict and explain the direction in which the position of equilibrium shifts after B2(g) is added.
Question 52
1 mark · Easy
Answer and see the solution →The equilibrium below is reached in a closed vessel:
State what happens to the position of equilibrium if some HI(g) is removed.
Question 53
3 marks · Easy
Answer and see the solution →Methanol (3e{CH3OH}) is produced in industry by the following equilibrium:
A technician increases the concentration of hydrogen gas (62e{H2}).
(a)[1 mark]State the effect on the position of equilibrium.
(b)[2 marks]Explain your answer in (a).
Question 54
2 marks · Easy
Answer and see the solution →The reaction below is at equilibrium:
At equilibrium, [Q] is 3.0 mol/dm^3 and [P] is 1.0 mol/dm^3. If 0.5 mol/dm^3 of Q is removed, what will [Q] be after the change is compensated and equilibrium is restored? Assume the system restores [Q] to the original value.
Question 55
5 marks · Easy
Answer and see the solution →This question is about reversibility in chemical reactions, especially in sealed containers.
(a)[2 marks]What is meant by a reversible reaction? State the symbol used to represent a reversible reaction in a chemical equation.
(b)Copper(II) sulfate crystals can lose water when heated and regain it when water is added.
(i)[1 mark]Write a balanced chemical equation using symbols to show the reversible change involving hydrated and anhydrous copper(II) sulfate.
(ii)[2 marks]What does it mean if this reaction occurs in a sealed container?
Question 56
5 marks · Easy
Answer and see the solution →This question is about dynamic equilibrium and how it is achieved in sealed containers.
(a)[2 marks]Explain what is meant by dynamic equilibrium in a reversible reaction.
(b)A chemical reaction is happening in a sealed container.
(i)[1 mark]Describe what happens to the concentrations of reactants and products once dynamic equilibrium is reached.
(ii)[2 marks]State the essential feature of the rates of the forward and reverse reactions at equilibrium in a sealed container.
Question 57
5 marks · Easy
Answer and see the solution →Reversible reactions often behave differently in sealed containers. Use your knowledge to answer the following questions.
(a)[2 marks]State one example of a reversible reaction and write its equation using the proper symbol.
(b)[2 marks]Explain why it is important for a container to be sealed when studying the equilibrium of a reversible reaction.
(c)[1 mark]Describe, with reference to sealed containers, how the forward and reverse reactions compare at dynamic equilibrium.