Question

(ii) Explain the purification of impure copper by electrolytic method giving a neat diagram.

Hint:

Electrolytic refining of copper helps obtain high-purity copper by dissolving the impure copper at the anode and depositing pure copper at the cathode.

Answer 1

Purification of Impure Copper by Electrolytic Method:
The process of purifying impure copper involves electrolytic refining. In this method, copper metal is refined using electrolysis. Here's how the process works: 1. Electrolyte:
The electrolyte used is a copper sulfate solution (CuSO\(_4\)) containing a small amount of sulfuric acid. 2. Anode and Cathode:
- The impure copper is used as the anode (positive electrode).
- A pure copper strip is used as the cathode (negative electrode).
3. Process:
When an electric current is passed through the electrolyte:
- Copper from the anode dissolves as Cu\(^{2+}\) ions into the solution.
- Cu\(^{2+}\) ions from the electrolyte are reduced to copper metal at the cathode, where pure copper is deposited.
- Impurities, such as silver, gold, and platinum, are left behind as anode mud.
The process is repeated until all the impurities are separated from the copper, and pure copper is deposited at the cathode. Diagram:
\includegraphics[width=0.5\linewidth]{image44.png} In the diagram above: - The impure copper (anode) is dissolved in the electrolyte, and pure copper is deposited on the cathode. Impurities are collected at the bottom as anode mud.