Question

How copper is refined with electrolytic method? Explain with necessary reaction?

Answer 1

The impurities present in copper are $Ag,Au,Fe,NiandZn$. Impure copper is electrolyticaly refined. Anode is made up of impure Cu. Cathode is made up of pure $Cu$. Electrolyte is acidified copper sulphate solution. At anode, Cu is oxidised to $C{u}^{2+}$ ions. $Cu\to C{u}^{2+}+2e^{-}$. At cathode, $C{u}^{2+}$ ions are reduced to Cu. $C{u}^{2+}+2e^{-}\to Cu$
Ag and Au (noble metals) do not react with dil sulphuric acid present in electrolyte and settle down as anode mud. Impurities of $Fe,NiandZn$ pass into electrolytic solution.