Answer the following questions with respect to the electrolytic process in the extraction of aluminum:

(i) Cryolite and fluorspar are components of the electrolyte. Addition of cryolite enhances the conductivity of the mixture since, pure alumina is almost a non-conductor of electricity. Addition of both cryolite & fluorspar lowers the fusion point of the mixture i.e., mixture fuses around 950°C instead of 2050°C.

(ii) The layer of powdered coke is sprinkled over the electrolytic mixture as :

1. it prevents burning of carbon electrodes in air at the emergence point from the bath.
2. it minimizes or prevents heat loss by radiation.