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
1–10 of 27 · Hard
Question 1
2 marks · Hard
Answer and see the solution →Describe one change you could make to the experiment measuring the rate of reaction between marble chips and hydrochloric acid that would allow the reaction to proceed more slowly. Explain your reasoning.
Question 2
5 marks · Hard
Answer and see the solution →A student performs an experiment to investigate the effect of temperature on the rate of reaction between marble chips and dilute hydrochloric acid. The reaction produces carbon dioxide gas, which is measured using a gas syringe. The student uses identical masses of marble chips and the same volume and concentration of acid at two different temperatures. The following data is recorded:
(a)Volume of CO₂ collected at 2 temperatures Time / min Volume of CO₂ at 20°C / cm³ Volume of CO₂ at 40°C / cm³ 0 0 0 1 18 40 2 27 60 3 31 62 4 33 62 (i)[2 marks]Calculate the average rate of reaction at 20°C in the first 2 minutes. Show your working.
(ii)[3 marks]Compare the rates of reaction at the two temperatures using the data. Give one reason, based on particle collisions, why the temperature affects the rate of reaction.
Question 3
2 marks · Hard
Answer and see the solution →Explain why a reaction mixture containing marble chips and dilute hydrochloric acid will still have some marble chips left at the end of the experiment.
Question 4
2 marks · Hard
Answer and see the solution →The reaction between excess potassium carbonate and dilute nitric acid is observed to slow down over time. Explain, using collision theory, why this happens.
Question 5
5 marks · Hard
Answer and see the solution →A student compares the rates of reaction between two samples of marble chips (calcium carbonate) and dilute phosphoric acid at room temperature. In experiment 1, large marble chips are used; in experiment 2, the marble chips are crushed into a fine powder. The same mass of marble and the same volume of acid are used in both experiments.
(a)[2 marks]State which experiment will have the faster initial rate of reaction, and give a reason using collision theory.
(b)[1 mark]Draw a suitable diagram to show the difference in surface area between the marble chips in experiment 1 and the powder in experiment 2.
(c)[2 marks]Explain, using collision theory, why the reaction stops even though there is excess marble in both experiments.
Question 6
2 marks · Hard
Answer and see the solution →A sealed flask contains hydrogen peroxide decomposing into water and oxygen gas. The reaction rate decreases over time. Use collision theory to explain why the rate gets slower, even though the temperature stays the same.
Question 7
2 marks · Hard
Answer and see the solution →A student investigates the reaction between magnesium and dilute hydrochloric acid. She uses two samples of magnesium of identical mass: one as a single strip and the other cut into many tiny pieces. State and explain how the rate of reaction will differ between the two samples.
Question 8
5 marks · Hard
Answer and see the solution →A student conducts an experiment to discover how changing the surface area of a solid affects the rate of its reaction with a liquid. She reacts 4.0 g of zinc with 25 cm³ of excess dilute sulfuric acid. She performs the same reaction twice:
(a)[2 marks]Describe a safe method she could use to compare the reaction rate using zinc granules and zinc powder, and state a measurement that would provide evidence for which reaction is faster.
(b)[2 marks]Explain, in terms of particle collisions, why the reaction rate changes when using zinc powder instead of granules.
(c)[1 mark]Suggest one other variable, apart from surface area, that must be kept the same to ensure a fair comparison.
Question 9
2 marks · Hard
Answer and see the solution →Explain, using collision theory, why a powdered solid reacts more quickly with a liquid than the same mass of solid in one lump.
Question 10
2 marks · Hard
Answer and see the solution →A student investigates the reaction between calcium carbonate and hydrochloric acid. State, with a reason, what happens to the rate of reaction if the concentration of hydrochloric acid is reduced to a third, assuming all other conditions remain the same.