A student investigated the electrolysis of copper(II) sulfate solution using copper electrodes to measure the mass of copper deposited at the cathode.
Table 1 shows the student's measurements and observations.
Table 1
| Mass of cathode (g) | Appearance of copper(II) sulfate solution | |
|---|---|---|
| Before electrolysis | 3.14 | clear blue solution |
| After electrolysis | 3.48 | clear blue solution |
Describe what steps the student must take to prepare the copper cathode after removing it from the electrolysis cell, before weighing it to get an accurate final mass.
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.