A student electrolyses blue copper sulfate solution using two electrodes made from the same material. The electrodes are either both copper or both inert.
| Electrode | Observation |
|---|---|
| Negative electrode | A pink-brown coating forms |
| Positive electrode | Bubbles of gas form |
Explain whether the electrodes are copper or inert.
Explain what happens to the blue colour of the solution as electrolysis continues.
76 exam-style questions on AQA GCSE Chemistry 4.3 Electrolysis, covering 4.3.1a The process of electrolysis, 4.3.1b Half equations in electrolysis, 4.3.2 Electrolysis of molten ionic compounds, 4.3.3 Using electrolysis to extract metals, 4.3.4 Electrolysis of aqueous solutions, and 4.3.5 Representation of reactions at electrodes as half equations. Each one has a worked solution and a mark scheme showing where the marks go.