A student investigated the electrolysis of nickel sulfate solution using a pure nickel cathode and an impure nickel anode.
The table below shows the measurements and observations from the experiment:
| Mass of cathode in g | Colour of nickel sulfate solution | |
|---|---|---|
| Before electrolysis | 4.15 | green solution |
| After electrolysis | 4.68 | green solution |
Explain why the green colour of the nickel sulfate solution did not change during the electrolysis.
83 exam-style questions on Edexcel GCSE Chemistry 4.2 Electrolytic processes, covering 4.2.1 Electrolytes and the process of electrolysis, 4.2.2 Products of electrolysis using inert electrodes, 4.2.3 Half equations, oxidation and reduction in electrolysis, and 4.2.4 Electrolysis of copper sulfate and purifying copper. Each one has a worked solution and a mark scheme showing where the marks go.