Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Catalysts in industry
19 practice questions
Practice questions
11–19 of 19
Question 11
3 marks · Normal
Answer and see the solution →The diagram below shows the energy changes in a reaction with and without a catalyst.
Reaction profile showing catalysed and uncatalysed paths. The activation energy for the uncatalysed reaction is 100 kJ/mol, and the activation energy for the catalysed reaction is 60 kJ/mol. The enthalpy change (ΔH) for the reaction is -40 kJ/mol.
Calculate the difference in activation energy between the catalysed and uncatalysed routes, and explain what effect this has on the rate of reaction.
Question 12
3 marks · Normal
Answer and see the solution →You are given an unknown white powder and asked to find out if it is a catalyst for the decomposition of hydrogen peroxide solution. Describe how you would show that this substance is a catalyst in the reaction.
Question 13
4 marks · Normal
Answer and see the solution →An industrial process uses iron as a catalyst for the reaction between nitrogen and hydrogen to form ammonia (the Haber process):
The data below show the percentage yield of ammonia at two different temperatures, with and without the iron catalyst.
Temperature/°C Catalyst present? Percentage yield of ammonia 400 No 15 400 Yes 15 500 No 10 500 Yes 10 Use the information in the table to answer the questions.
(a)[1 mark]Does the iron catalyst affect the percentage yield of ammonia at these temperatures? Explain your answer.
(b)[2 marks]Explain why the use of the iron catalyst is still important in this industrial process.
(c)[1 mark]Suggest one economic benefit of using a catalyst in the Haber process.
Question 14
1 mark · Normal
Answer and check →Which statement best describes how a catalyst speeds up a reaction?
- A.A catalyst increases the total enthalpy change (ΔH) of a reaction.
- B.A catalyst provides an alternative pathway with lower activation energy.
- C.A catalyst makes the products more stable.
- D.A catalyst increases the concentration of reactants.
Question 15
2 marks · Normal
Answer and see the solution →Draw a reaction profile diagram for a reaction with and without a catalyst. Clearly label the energy of reactants, energy of products, activation energy with and without catalyst, and the enthalpy change (ΔH).
Question 16
4 marks · Normal
Answer and see the solution →You want to test whether a black solid is a catalyst for the decomposition of hydrogen peroxide solution.
(a)[2 marks]Describe how you would carry out the experiment to test if the black solid is a catalyst.
(b)[2 marks]Explain how you would show that the black solid is unchanged after the reaction.
Question 17
5 marks · Hard
Answer and see the solution →The diagram below shows the energy changes during a chemical reaction.
(a)[2 marks]Explain, in terms of activation energy, how a catalyst increases the rate of a reaction.
(b)[2 marks]A student suggests that adding a catalyst would change the total enthalpy change (ΔH) of a reaction. Is this correct? Explain your answer.
(c)[1 mark]Describe, using a reaction profile diagram, what happens to the activation energy and enthalpy change of a reaction when a catalyst is used.
Question 18
2 marks · Hard
Answer and see the solution →Describe two key features that should be shown on a reaction profile diagram to illustrate the effect of a catalyst on a reaction.
Question 19
2 marks · Hard
Answer and see the solution →Ammonia is produced in the Haber process, which requires high temperatures and pressures. The process uses an iron catalyst.
Explain two ways that using a catalyst in the Haber process is important for the chemical industry.