Aluminium is extracted in the electrolysis of :

Aluminium is extracted by

Calcium is extracted by the electrolysis of :

Calcium is extracted by the electrolysis of :

Calcium is extracted by the electrolysis of:

Sodium metal is extracted by the electrolysis of -

Sodium metal is extracted by the electrolysis of -

Sodium metal is extracted by the electrolysis of

In an electrolytic tank, aluminium metal is being extracted by the electrolysis of molten aluminium oxide using carbon electrodes. It is observed that one of the carbon electrodes is gradually burnt aay and has to be replaced. (a) Which carbon electrode (cathode or anode) is burnt away? (b) why is this carbon electrode burnt away?