$AgCl$ on fusion with sodium carbonate,gives

The addition of silica during the extraction of copper from its sulphide ore:

Explain electrometallurgy in detail.

Which of the following reduction reactions $CANNOT$ be carried out with coke?

Refractory materials are generally used in furnaces because

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A):$ Aluminium is extracted from bauxite by the electrolysis of a molten mixture of $Al_2O_3$ with cryolite.
Reason $(R):$ The oxidation state of $Al$ in cryolite is $+3$.
In the light of the above statements,choose the most appropriate answer from the options given below: