Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
881–890 of 991
Question 881
4 marks · Normal
Answer and see the solution →A student electrolyses concentrated sodium chloride solution for several minutes and records the following results:
Volume of gases collected at electrodes during electrolysis Electrode Gas Volume collected (cm³) Cathode Hydrogen 20 Anode Chlorine 14 (a)[1 mark]State the product collected at the cathode.
(b)[1 mark]State the product collected at the anode.
(c)[1 mark]Suggest a reason why less chlorine was collected than hydrogen.
(d)[1 mark]Explain how the results could be used to confirm the identity of the hydrogen gas.
Question 882
1 mark · Normal
Answer and check →Which statement best explains why less chlorine gas is collected at the anode than expected when electrolysing concentrated sodium chloride solution?
- A.The chlorine evaporates quickly.
- B.Water reacts with the chlorine to make sodium hydroxide.
- C.Some chlorine dissolves in the solution.
- D.Chloride ions are less reactive than sodium ions.
Question 883
2 marks · Normal
Answer and see the solution →Give two observations you could make during the electrolysis of concentrated sodium chloride solution that would indicate a reaction is taking place.
Question 884
4 marks · Normal
Answer and see the solution →Describe the products formed at the electrodes during the electrolysis of concentrated sodium chloride solution, and test how you could confirm their presence.
(a)[2 marks]State the product formed at the cathode and describe its relevant test.
(b)[2 marks]State the product formed at the anode and describe its relevant test.
Question 885
2 marks · Hard
Answer and see the solution →Describe two essential safety precautions you must take when setting up an experiment to investigate the electrolysis of concentrated sodium chloride solution in the laboratory.
Question 886
5 marks · Hard
Answer and see the solution →A student carries out the electrolysis of concentrated sodium chloride solution using carbon electrodes as shown below.
Electrolysis of concentrated sodium chloride solution (a)[1 mark]State the product formed at the cathode.
(b)[1 mark]State the product formed at the anode.
(c)[1 mark]Write the half-equation for the reaction at the cathode.
(d)[1 mark]Write the half-equation for the reaction at the anode.
(e)[1 mark]Explain why hydrogen forms at the cathode instead of sodium.
Question 887
2 marks · Hard
Answer and see the solution →During the electrolysis of concentrated sodium chloride solution, the volume of chlorine gas collected at the anode is often less than the volume expected. Explain two reasons for this observation.
Question 888
1 mark · Easy
Answer and see the solution →During the electrolysis of sodium chloride solution, what ion builds up near the cathode making the solution there alkaline?
Question 889
3 marks · Easy
Answer and see the solution →A student electrolyses sodium chloride solution and is surprised that hydrogen, not sodium, is produced at the cathode.
(a)[1 mark]Name the two positive ions present in the solution that could be discharged at the cathode.
(b)[1 mark]State which of these ions is discharged and forms a gas at the cathode.
(c)[1 mark]Explain why sodium ions are not discharged at the cathode.
Question 890
2 marks · Easy
Answer and see the solution →Write a balanced half-equation for the cathode reaction during the electrolysis of sodium chloride solution when hydrogen gas is formed.