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
361–370 of 407 · Easy
Question 361
2 marks · Easy
Answer and see the solution →A student finds that the volume of chlorine gas collected during the electrolysis of concentrated sodium chloride solution is less than expected.
(a)[1 mark]Explain why less chlorine gas is collected than expected.
(b)[1 mark]Suggest one way you could change the experiment to collect more chlorine gas.
Question 362
1 mark · Easy
Answer and see the solution →Name one piece of apparatus you would need to collect the gas produced at the cathode during the electrolysis of concentrated sodium chloride solution.
Question 363
3 marks · Easy
Answer and see the solution →The electrolysis of concentrated sodium chloride solution is carried out using carbon electrodes.
(a)[1 mark]State the product formed at the cathode.
(b)[1 mark]State the product formed at the anode.
(c)[1 mark]Write a word equation for the reaction that occurs at the anode.
Question 364
2 marks · Easy
Answer and see the solution →In an experiment, 12 cm³ of hydrogen gas is collected at the cathode during the electrolysis of concentrated sodium chloride solution. The theoretical volume of chlorine expected at the anode is also 12 cm³, but only 7 cm³ is collected.
Calculate the difference between the expected and the actual volume of chlorine collected. Explain why there is this difference.
Question 365
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 366
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 367
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.
Question 368
2 marks · Easy
Answer and see the solution →Describe why the region near the cathode becomes alkaline during the electrolysis of sodium chloride solution.
Question 369
3 marks · Easy
Answer and see the solution →The table shows the tendency to gain electrons (ease of reduction) for some ions in decreasing order.
Reduction Tendency of Some Ions Ion Reduction Tendency K^+ Very difficult Na^+ Very difficult Ca^2+ Difficult H^+ Easier Cu^2+ Very easy A student electrolyses sodium chloride solution. Use the data to answer the following questions.
(a)[1 mark]Suggest which ion, Na⁺ or H⁺, is more easily reduced at the cathode.
(b)[1 mark]Which gas is formed at the cathode?
(c)[1 mark]Explain why sodium metal does not form at the cathode, using the reduction tendency data.
Question 370
1 mark · Easy
Answer and see the solution →What is the symbol equation for the reduction of hydrogen ions at the cathode during electrolysis of sodium chloride solution?