Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Electrolysis
198 practice questions
Topics covered
- Why things conduct electricity17 practice questions
- Passing electricity through compounds: electrolysis20 practice questions
- The electrolysis of molten compounds19 practice questions
- Electrolysis and redox19 practice questions
- The electrolysis of other molten substances19 practice questions
- The electrolysis of aqueous solutions18 practice questions
- The electrolysis of sodium chloride solution19 practice questions
- The electrolysis of copper(ii) sulfate solution using inert electrodes18 practice questions
- The electrolysis of some other solutions using inert electrodes19 practice questions
- What would happen with non-electrolytes?19 practice questions
Practice questions
171–180 of 198
Question 171
2 marks · Easy
Answer and see the solution →Explain why sodium chloride conducts electricity when molten, but not as a solid.
Question 172
3 marks · Easy
Answer and see the solution →A student tests three substances for their ability to conduct electricity when solid and when dissolved in water. The results are shown in the table.
Conductivity results Substance Conducts as a solid? Conducts dissolved in water? A (potassium bromide) No Yes B (ethanol) No No C (magnesium) Yes n/a (a)[2 marks]Identify substances A, B, and C as ionic, covalent, or metallic.
(b)[1 mark]Which substance is a non-electrolyte?
Question 173
1 mark · Easy
Answer and see the solution →Name a common non-electrolyte used in food and explain why it does not conduct electricity.
Question 174
3 marks · Easy
Answer and see the solution →The table gives the results for the electrical conductivity of three substances in different states:
Conductivity results for different substances Substance Solid Molten Aqueous D No Yes Yes E No No No F Yes Yes n/a (a)[1 mark]Which substance is a non-electrolyte? Explain your answer.
(b)[1 mark]What type of bonding does substance D have? Explain using the data.
(c)[1 mark]State the bonding present in substance F.
Question 175
2 marks · Easy
Answer and see the solution →A student tests solid sodium chloride and sugar for electrical conductivity. She finds that only molten sodium chloride conducts electricity, while sugar does not conduct electricity when molten or in solution.
State, with a reason, whether each substance is ionic, covalent, or a non-electrolyte.
(a)[1 mark]Sodium chloride:
(b)[1 mark]Sugar:
Question 176
2 marks · Easy
Answer and see the solution →The results of an experiment are shown below:
Conductivity Results Substance State Tested Conducts Electricity? Magnesium chloride Solid No Magnesium chloride Molten Yes Ethanol Liquid No Identify whether each substance is ionic, covalent, or a non-electrolyte. Give a reason for your answer in each case.
(a)[1 mark]Magnesium chloride:
(b)[1 mark]Ethanol:
Question 177
2 marks · Normal
Answer and see the solution →A student wants to know whether glucose (C6H12O6) is an electrolyte, an ionic compound, or a covalent compound. They attempt to pass an electric current through both solid glucose and glucose dissolved in water, but the bulb does not light up in either case.
State what type of substance glucose is and give a reason based on the results of the experiment.
Question 178
4 marks · Normal
Answer and see the solution →Two students investigate the ability of different substances to conduct electricity using the apparatus below.
(a)[2 marks]Complete the table below by identifying whether each substance is likely to conduct electricity or not in the form stated.
Substance State Will it conduct electricity? (Yes/No) Sodium chloride Molten Sucrose (C12H22O11) Aqueous solution (b)[2 marks]Explain why one of these substances does not conduct electricity in the given state.
Question 179
3 marks · Normal
Answer and see the solution →Water is often used as the solvent in electrolysis experiments. Pure water conducts electricity only very weakly, but when a small amount of sodium chloride is added, it conducts electricity much better.
Explain why pure water is a poor conductor of electricity and why adding sodium chloride increases the conductivity so much.
Question 180
4 marks · Normal
Answer and see the solution →The table below shows results from an experiment where a student measured the volume of oxygen gas produces at the anode when different substances are electrolysed:
Results of electrolysis Substance (aq) Bulb lights? Volume of O2 at anode (cm³) Sodium sulfate Yes 18.5 Copper(II) sulfate Yes 17.8 Sugar No 0 Ethanol No 0 (a)[2 marks]Identify which substances are electrolytes and which are non-electrolytes. Explain your choices.
(b)[2 marks]State what this experiment shows about the type of bonding in sugar and ethanol.