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
31–40 of 69 · Normal
Question 31
2 marks · Normal
Answer and see the solution →A reaction between powdered magnesium and dilute hydrochloric acid releases 0.30 g of hydrogen in the first 20 seconds. Calculate the average rate of production of hydrogen gas in g/s.
Question 32
4 marks · Normal
Answer and see the solution →Look at the following graph, which shows the rate of reaction (y-axis, in g/s) against concentration of hydrochloric acid (x-axis, in mol/dm³) for a certain reaction.
Rate of reaction vs concentration of HCl (a)[1 mark]Describe the shape and position of the line on the graph.
(b)[1 mark]What does this show about the relationship between the concentration of hydrochloric acid and the rate of reaction?
(c)[2 marks]If the concentration is doubled, what happens to the rate of reaction? Explain your answer.
Question 33
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 34
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 35
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 36
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 37
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 38
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.
Question 39
2 marks · Normal
Answer and see the solution →Describe the effect of increasing the pressure on a reaction between two gases, and link your answer to particle collisions.
Question 40
4 marks · Normal
Answer and see the solution →(a)[1 mark]State whether changing the pressure has a significant effect on the rate of reaction for solids or liquids.
(b)[2 marks]Describe the arrangement of particles in solids and in liquids.
(c)[1 mark]Explain, using your answer to (b), why pressure does not change the rate much for solids and liquids.