Question

Describe the role of the following :
(i) NaCN in the extraction of silver ore.
(ii) Cryolite in the extraction of aluminium from pure alumina.

Answer 1

(i) Na CN is used to form soluble complex of cyanide while impurities remain unaftected.
(ii) To make laumina a good conductor of electricity and to low down the melting point of both from 2323 k to 1140 k