A student investigates the electrolysis of aqueous solutions of ionic compounds.
| Aqueous solution | Product at cathode | Product at anode |
|---|---|---|
| Copper sulfate | Copper | Oxygen |
| Potassium chloride | Hydrogen | Chlorine |
| Copper chloride | Copper | Chlorine |
| Sulfuric acid | Hydrogen | Oxygen |
Write the formulae of the ions that are present in aqueous sodium chloride solution.
Why is it important that the investigation is done with inert electrodes?
Electroplating is used to cover a metal with another metal.
Which aqueous solution would you use to electroplate a metal ring with copper using a safe method?
Give two reasons for your answer to (c)(i).
Predict the product made at the anode when potassium sulfate solution is electrolysed.
Hydrogen gas is made at the cathode instead of potassium metal. Explain why.
Write the balanced half-equation for the formation of hydrogen gas. Use e−\text{e}^-e− to represent an electron.
The electrolysis products of ionic compounds can be different in molten or aqueous states. Suggest why.
34 exam-style questions on OCR GCSE Chemistry Electrolysis. Each one has a worked solution and a mark scheme showing where the marks go.