The cathode used in the electrolytic cell of aluminium extraction is made of

Options

A. aluminium
B. carbon lining
C. iron
D. steel

Answer

### Step-by-Step Solution:

1. **Understanding the Electrolytic Cell**: In the extraction of aluminum, an electrolytic cell is used. This cell consists of two electrodes: an anode and a cathode.

2. **Identifying the Anode and Cathode**: In the electrolytic cell for aluminum extraction, the iron container acts as the anode, while the cathode is made of a different material.

3. **Material of the Cathode**: The cathode in the electrolytic cell for aluminum extraction is made of carbon lining. This is because carbon can withstand the high temperatures and corrosive environment of the electrolysis process.

4. **Role of Graphite Rods**: To facilitate the reaction, graphite rods are also used in the process. Graphite is a form of carbon that helps in conducting electricity and allows the electrolysis to occur more efficiently.

5. **Alumina as the Source Material**: The source material for aluminum extraction is alumina (Al2O3), which is derived from bauxite ore. During the electrolysis, alumina is dissolved in a molten solvent, which includes cryolite and fluorite, to lower the melting point and improve conductivity.

6. **Conclusion**: Therefore, the correct answer to the question is that the cathode used in the electrolytic cell of aluminum extraction is made of carbon lining.

### Final Answer:
The cathode used in the electrolytic cell of aluminum extraction is made of **Carbon lining**.

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