Question

The chemical that is added to reduce the melting point of the reaction mixture during the extraction of aluminium is ______.

Options

• Cryolite

• Bauxite

• Calamine

• Kaolite official

Answer 1

The chemical that is added to reduce the melting point of the reaction mixture during the extraction of aluminium is cryolite.

Explanation:

During the extraction of aluminium by the Hall–Héroult process, cryolite (Na₃AlF₆) is added to the mixture. It acts as a flux and lowers the melting point of pure alumina (Al₂O₃) from about 2323 K to 1173 K, making electrolysis easier and more economical. It also increases the electrical conductivity of the molten mixture.