Explain why :
(a) In the electrolysis of alumina using the Hall Heroult’* Process the electrolyte is covered with powdered coke.
(b) During galvanization, iron sheets are coated with zinc during galvanization.
(a) It prevents burning of carbon anodes and prevents heat loss from the molten electrolyte.
(b) Zinc forms a protecting coating on the surface of iron and hence prevents it from rusting. Zinc by itself form a protective layer of zinc oxide and hence does not tarnish.
