Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Reversible reactions in a sealed container
18 practice questions
Practice questions
1–10 of 18
Question 1
3 marks · Easy
Answer and see the solution →This question is about sealed containers and reversible reactions.
(a)[1 mark]State what a sealed container means in the context of a chemical reaction.
(b)[1 mark]Give one reason why using a sealed container is important when studying reversible reactions.
(c)[1 mark]Suggest one thing that is allowed to change in a sealed container during a reaction.
Question 2
2 marks · Easy
Answer and see the solution →The thermal decomposition of solid ammonium chloride is a reversible reaction.
Explain why both ammonia and hydrogen chloride gases are observed inside the sealed tube during heating, and why a white solid appears again above the heated area.
Question 3
3 marks · Easy
Answer and see the solution →A student records the number of red and green squares at different times in a sealed container during a reversible reaction.
Time (s) Red squares Green squares 0 40 0 1 30 10 2 23 17 3 19 21 (a)[1 mark]How many total squares are there in the container at each recorded time?
(b)[1 mark]What does this suggest about the system in the container?
(c)[1 mark]State what feature of the container ensures this result in a reversible reaction.
Question 4
1 mark · Easy
Answer and see the solution →State what term is used when the rate of the forward reaction equals the rate of the backward reaction in a sealed system.
Question 5
3 marks · Easy
Answer and see the solution →When heating ammonium chloride in a sealed test tube, a reversible reaction takes place.
(a)[1 mark]Write a chemical equation to show the decomposition of ammonium chloride on heating.
(b)[1 mark]State the names of the products formed during the decomposition.
(c)[1 mark]Give a reason why the reaction is reversible.
Question 6
1 mark · Easy
Answer and see the solution →State the chemical formula of the white solid that forms when ammonia and hydrogen chloride gases react together in a sealed tube.
Question 7
2 marks · Easy
Answer and see the solution →A reversible reaction occurs in a sealed container. At the start, there are 80 blue squares representing reactant molecules. Every second, one fifth of the blue squares turn yellow (product molecules). After one second, how many blue squares remain? Show your calculation.
Question 8
2 marks · Normal
Answer and see the solution →State what is meant by a sealed container in the context of reversible reactions. Give two essential features.
Question 9
4 marks · Normal
Answer and see the solution →A reversible reaction takes place in a sealed flask. At first, only reactants are present. The forward reaction starts quickly, but slows down over time.
(a)[1 mark]Explain why the rate of the forward reaction decreases as the reaction proceeds.
(b)[1 mark]Describe what is happening with the reverse reaction as the products begin to form.
(c)[1 mark]State what is meant by equilibrium in this context.
(d)[1 mark]Explain why equilibrium can only be reached in a sealed container.
Question 10
3 marks · Normal
Answer and see the solution →Explain, with reasons, why a sealed container is necessary for studying reversible reactions.