Answer:
Option C
Explanation:
Aluminium is refined by Hoope's process.This process contains, carbon electrodes, which are used as cathode and iron tank linked with carbon bricks as an anode.
The electrolyte contains three layers
(i)Bottom layer is made by using impure aluminium
(ii) A molten mixture of fluorides of sodium (Na3AlF6) Ba and Al and Al2O3 is used to make the middle layer
(iii) At the top, there is a layer of pure molten aluminium
When an electric current is passed pure aluminium metal is deposited at cathode from the middle layer and an equivalent amount of Al moves from the bottom layer to middle layer leaving behind the impurities
