A solution containing copper ions is electrolysed. The mass of the cathode and the concentration of copper ions in the solution are measured before and after electrolysis.
| Measurement | Before electrolysis | After electrolysis |
|---|---|---|
| Mass of cathode | 12.40 g | 12.76 g |
| Concentration of copper ions | 0.80 g/dm³ | 0.50 g/dm³ |
Explain the changes in the measurements.
136 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.