Question

[TBQ.V.(4)]
Write scientific reasons.
Anodes need to be replaced from time to time during the electrolysis of alumina.

Answer 1

• During electrolysis of alumina, the oxygen liberated at the carbon anode reacts with graphite rods (carbon anode) and forms carbon dioxide.
• As the anodes get oxidised during electrolysis of alumina, they are continuously eroded. Hence, it is necessary to replace anodes from time to time.