Question

In the commercial electrochemical process for aluminium extraction, electrolyte used is
(a) Al(OH)3 is NaOH solution.
(b) An aqueous solution of Al2 (SO4)3.
(c) A molten mixture of Al2O3 and Na3AlF6.
(d) A molten mixture of Al2O3 and Al(OH)3.

Answer 1

Answer:

Al(OH)3 in NaOH solution. b). An aqueous solution of Al2(SO4)3. c). A molten mixture of Al2O3 and Na3AlF6. d). A molten mixture of

Answer 2

Answer:

(c)

Explanation:

The electrolysis of pure alumina faces some difficulties. Pure alumina is a bad conductor is of electricity. This fusion temperature of pure alumina is about 2000∘C, and at this temperature, when the electrolysis is carried out on the fused mass, the metal formed vaporises as the boiling point of aluminium is 1800∘C. These difficulties are overcome by using a mixture containing alumina, cryolite (Na3AlF6), and (CaF2).