Question

How are metals refined by the electrolytic methods?

Answer 1

Electrolytic method : This method is based upon the phenomenon of electrolysis and is widely used to refine a number of metals such as copper, silver, gold etc. In
this method, impure metal is made anode whereas a thin sheet of pure metal is used as cathode in an electrolytic tank. The electrolyte used in the tank is usually the acidified aqueous solution of a salt or complex salt of metal. On passing the electric current through electrodes the metal ions from anode go into the electrolyte solution. These cations gain electrons from the cathode and get deposited on it. The impurities either remain dissolved or get precipitated as anode mud.
At anode : M → Mⁿ + ne^-
At cathode: Mⁿ + ne^-  → M where M is the metal to be refined .