How To Extract Aluminium By Electrolysis

The video explains the process of extracting aluminum using electrolysis. Aluminum is extracted from bauxite, which is purified to yield aluminum oxide. Due to its high melting point, aluminum oxide is dissolved in cryolite to lower the melting point, making the process more cost-effective. The electrolysis process involves graphite electrodes, where aluminum forms at the cathode and oxygen forms at the anode, reacting with carbon to produce carbon dioxide. This reaction causes the anode to wear away, necessitating regular replacement. The process is energy-intensive, contributing to its high cost.

What is the primary ore from which aluminum is extracted?

• Alumina

• Bauxite

• Cryolite

• Graphite

Why is cryolite used in the electrolysis of aluminum oxide?

• It lowers the melting point of aluminum oxide.

• It acts as a catalyst in the reaction.

• It provides the necessary ions for the reaction.

• It increases the melting point of aluminum oxide.

What forms at the negative cathode during the electrolysis of aluminum oxide?

• Oxygen gas

• Graphite

• Carbon dioxide

• Aluminum metal

What happens to the oxygen ions at the positive anode during electrolysis?

• They are reduced to form oxygen gas.

• They remain unchanged.

• They react with carbon to form carbon dioxide.

• They combine with aluminum ions.

Why is the extraction of aluminum considered expensive?

• Due to the high cost of bauxite.

• Because of the large amount of electricity required.

• Due to the high melting point of aluminum.

• Because cryolite is rare and costly.