Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Physical Chemistry
442 practice questions
Topics covered
Practice questions
221–230 of 442
Question 221
2 marks · Normal
Answer and see the solution →State what a catalyst is and explain why the same catalyst can be used again in another reaction of the same type.
Question 222
4 marks · Normal
Answer and see the solution →(a)[2 marks]Write a word equation and a balanced symbol equation for the catalytic decomposition of hydrogen peroxide.
(b)[2 marks]Explain why manganese(IV) oxide is described as a catalyst in this reaction.
Question 223
3 marks · Normal
Answer and see the solution →Explain, with reasons, how you could show experimentally that manganese(IV) oxide is not chemically changed during the decomposition of hydrogen peroxide.
Question 224
4 marks · Normal
Answer and see the solution →The table shows the volume of oxygen gas collected over 60 seconds when hydrogen peroxide is decomposed using three different solids as potential catalysts. The experiment used the same conditions (temperature, concentration, volumes).
Oxygen collected over time Time (s) MnO2 (cm³) PbO2 (cm³) CuO (cm³) 0 0 0 0 20 24 8 0 40 36 13 0 60 40 16 0 (a)[2 marks]Compare the effectiveness of the three solids as catalysts for this reaction.
(b)[2 marks]Using evidence from the data, explain your answer.
Question 225
1 mark · Normal
Answer and check →Which statement best describes the role of a catalyst?
- A.A catalyst increases the rate of a reaction and is chemically unchanged at the end.
- B.A catalyst is used up during the reaction.
- C.A catalyst stops chemical reactions from taking place.
- D.A catalyst increases the yield of products in a reaction.
Question 226
2 marks · Normal
Answer and see the solution →Give two reasons why catalysts are important in industrial chemical processes.
Question 227
4 marks · Normal
Answer and see the solution →(a)[2 marks]Describe how you would set up an experiment to measure the effect of different solid catalysts on the rate of decomposition of hydrogen peroxide.
(b)[1 mark]State one safety precaution you would take when carrying out this experiment.
(c)[1 mark]What result would show that a solid is not a catalyst for this reaction?
Question 228
3 marks · Normal
Answer and see the solution →A chemistry student investigates the decomposition of hydrogen peroxide ( ) by measuring the volume of oxygen gas produced in 60 seconds, with and without a catalyst present. The results are:
Experiment Catalyst present? Volume of O produced/cm (in 60 s) 1 No 2.5 2 Yes 22.0 a) Calculate the average rate of oxygen production (in cm/s) for Experiment 1.
b) Calculate the average rate of oxygen production (in cm/s) for Experiment 2.
c) By how many times does the catalyst increase the rate of oxygen production compared to the experiment without a catalyst? Give your answer to 1 decimal place.
(a)[1 mark]Calculate the average rate of oxygen production for Experiment 1.
(b)[1 mark]Calculate the average rate of oxygen production for Experiment 2.
(c)[1 mark]By how many times does the catalyst increase the rate of oxygen production compared to the experiment without a catalyst? Give your answer to 1 decimal place.
Question 229
2 marks · Hard
Answer and see the solution →State two features that are always true for catalysts when used in a chemical reaction.
Question 230
5 marks · Hard
Answer and see the solution →A student investigates the reaction below:
(a)[2 marks]Describe how the student could show that manganese(IV) oxide acts as a catalyst in this reaction.
(b)[2 marks]After the reaction, the student filters, dries, and reweighs the manganese(IV) oxide. The mass is unchanged. Explain why this result supports the conclusion that manganese(IV) oxide is a catalyst.
(c)[1 mark]State why only a small amount of catalyst is usually needed for a reaction.