$(i)$ Define the term 'anode mud'. Name the electrode made of pure metal.
$(ii)$ Give the reactions taking place at cathode and at anode during the electrolytic refining of copper.

(N/A) $(i)$ The insoluble impurities that settle down at the bottom of the anode during electrolytic refining are known as 'anode mud'. The cathode is made of a thin strip of pure metal.
$(ii)$ During the electrolytic refining of copper:
At anode: $Cu(s) \rightarrow Cu^{2+}(aq) + 2e^-$
At cathode: $Cu^{2+}(aq) + 2e^- \rightarrow Cu(s)$