An electrochemist investigated how the mass of copper deposited on a steel cathode varied with the electric current during the electrolysis of an acidic copper(II) sulfate solution. The electrolysis was carried out for exactly 15 minutes in each run.
The results are shown in Table 1.
| Current (A) | Mass of copper deposited (g) |
|---|---|
| 0.0 | 0.00 |
| 0.5 | 0.15 |
| 1.0 | 0.30 |
| 1.5 | 0.44 |
| 2.0 | 0.59 |
| 2.5 | 0.74 |
State and explain the trend shown in these results.
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.