Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Rates of Reaction
164 practice questions
Topics covered
- Experiments to measure the rate of reaction19 practice questions
- Explaining what's happening19 practice questions
- Changing the surface area of the reactants19 practice questions
- Changing the concentration of the reactants19 practice questions
- Changing the pressure on the reaction19 practice questions
- What are catalysts?19 practice questions
- How does a catalyst work?20 practice questions
- Catalysts in industry19 practice questions
Practice questions
81–90 of 164
Question 81
3 marks · Easy
Answer and see the solution →The table shows the completion time for a reaction between two gases at different pressures.
Reaction time at different pressures Pressure / kPa Completion time / min 80 20 160 10 240 6.7 (a)[1 mark]Describe the relationship between pressure and completion time for this reaction.
(b)[2 marks]Explain, using particle theory, why increasing the pressure causes this effect.
Question 82
1 mark · Easy
Answer and see the solution →State why changing the pressure has little effect on the rate of a reaction involving only liquids.
Question 83
3 marks · Easy
Answer and see the solution →Consider a reaction between two gases in a sealed container.
(a)[1 mark]Describe what happens to the rate of reaction if the pressure of the gases is increased.
(b)[2 marks]State why this happens, linking your answer to particle collisions.
Question 84
2 marks · Easy
Answer and see the solution →A student compresses a liquid to try to double the rate of reaction. The initial time taken for the reaction is 30 minutes. Calculate the likely time taken to complete the reaction after the pressure is doubled. Explain your answer.
Question 85
2 marks · Normal
Answer and see the solution →State what happens to the rate of a reaction involving gases when the pressure is increased. Briefly explain your answer.
Question 86
4 marks · Normal
Answer and see the solution →(a)[1 mark]A student increases the pressure in a chemical reaction involving only solids. Predict what effect, if any, this has on the rate of reaction.
(b)[2 marks]Explain why changing the pressure has little effect on the rate of reaction for solids. Use particle arrangement in your answer.
(c)[1 mark]Would increasing the pressure have a similar effect on a reaction involving only liquids? Explain your answer.
Question 87
3 marks · Normal
Answer and see the solution →A reaction between two gases at 100 kPa takes 10 minutes to complete. If the pressure is increased to 200 kPa, assume the rate doubles. Calculate the new time for the reaction to complete.
Show your working.
Question 88
3 marks · Normal
Answer and see the solution →Explain, using particle theory, why changing the pressure has little effect on the rate of reactions involving only liquids.
Question 89
4 marks · Normal
Answer and see the solution →The table below shows the time taken for a reaction between two gases at different pressures.
Reaction time at different pressures Pressure (kPa) Time to complete reaction (s) 50 40 100 20 200 10 (a)[1 mark]Describe how the time taken changes as the pressure increases.
(b)[2 marks]Calculate how many times faster the reaction is at 200 kPa compared to 50 kPa.
(c)[1 mark]Explain why the reaction is faster at higher pressures.
Question 90
1 mark · Normal
Answer and check →Which statement best explains why increasing the pressure of a reaction involving only liquids has little effect on the rate?
- A.Liquid particles are already close together, so increasing pressure does not significantly increase the number of collisions.
- B.Increasing pressure causes liquids to evaporate quickly.
- C.Higher pressure breaks down liquid molecules.
- D.Liquids expand a lot when pressure changes.