Question

The graphite electrodes in the extraction of âaluminiumâ by Hall-Heroult process need to be changed frequently. Why?

Answer 1

The graphite rods in the extraction of aluminium gets oxidised from carbon to carbon dioxide and this is called burning of anode.
# A student of class 10.
# hope it helps.

Answer 2

HEYY FRIEND!

In Hall-Heroult's process, temperature that is maintained is 950 degree Celcius, which is indeed a very high temperature.

At this temperature, the oxygen gas produced at the anode reacts with the graphite anode, forming carbon dioxide gas. Thus, the surface area of GRAPHITE ANODE gradually decreases.

So, the anode needs to be changed from time to time.

THANKS!