*(d) Impure copper can be purified using electrolysis. In this electrolysis • the anode is made of impure copper • the cathode is made from pure copper • the electrolyte is copper sulfate solution. The apparatus at the start of the experiment is shown in Figure 7.
During the electrolysis three observations are made
• the sizes of both the anode and the cathode change
• a solid appears directly beneath the anode
• the colour of the copper sulfate solution does not change. Explain all three observations.
