Table 1 shows the mass of a copper cathode and the appearance of the aqueous copper(II) sulfate electrolyte before and after an electrolysis experiment using copper electrodes.
| Mass of copper cathode (g) | Appearance of copper(II) sulfate solution | |
|---|---|---|
| Before electrolysis | 5.20 | Clear, blue solution |
| After electrolysis | 5.85 | Clear, blue solution |
Explain, in terms of ions, the change in mass of the cathode shown in Table 1.
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.