Question

(ii) What do you understand by Electrolytic refining? Explain with diagram.

Hint:

Electrolytic refining is used for high-purity metals like copper and silver, where the impurities are left behind or dissolve in the electrolyte.

Answer 1

Electrolytic Refining:
Electrolytic refining is a process used to purify metals, particularly non-ferrous metals like copper, silver, and gold. It involves using electrolysis to remove impurities from a metal, leaving behind pure metal at the cathode. In this method, a metal is made to act as the anode, and a pure strip of the same metal is used as the cathode. The electrolyte contains a salt of the metal to be purified. During the electrolysis, the metal ions are reduced at the cathode, and impurities are left behind or dissolve into the electrolyte. Process:
1. The impure metal is used as the anode. 2. A pure metal strip is used as the cathode. 3. The electrolyte is a solution containing the salt of the metal being purified. 4. During electrolysis, the metal ions from the anode dissolve into the electrolyte and move to the cathode, where they are reduced to pure metal. Diagram:
\[ \text{Electrolytic Refining of Copper} \] \begin{center} \begin{tikzpicture} \draw (0,0) rectangle (6,2); \draw[->] (3,0) -- (3,-1) node[midway, right] {Impure Copper (Anode)}; \draw[->] (3,2) -- (3,3) node[midway, right] {Pure Copper (Cathode)}; \draw (6,-1) node[right] {Electrolyte (CuSO}_4\text{)}; \end{tikzpicture} \end{center} Conclusion:
Electrolytic refining is an effective method for purifying metals, especially copper, where the electrolysis process separates the metal from its impurities. This ensures the metal obtained is of high purity.