A technician wants to coat a small metal key with a layer of a different metal by electrolysis. The key is used as the cathode and a graphite rod is used as the anode.
The technician can use either magnesium nitrate solution or copper(II) nitrate solution as the electrolyte.
Which solution should the technician use to coat the key? Justify your answer.
98 exam-style questions on OCR GCSE Chemistry 3.4 Electrolysis, covering 3.4.1 Products formed at the electrodes in electrolysis and 3.4.2 The technique of electrolysis. Each one has a worked solution and a mark scheme showing where the marks go.