Zinc is obtained from zinc blende by:

The chemical reaction that involves the roasting process is:

Which process is used to convert hydrated alumina into anhydrous alumina?

Match the following:

List-$I$	List-$II$
$(I)$ Calcination	$a. Fe_2O_3 \cdot nH_2O \rightarrow Fe_2O_3 + nH_2O$
$(II)$ Roasting	$b. 2Cu_2S + 3O_2 \rightarrow 2Cu_2O + 2SO_2$
$(III)$ Flux	$c. SiO_2 + FeO \rightarrow FeSiO_3$
$(IV)$ Thermite	$d. Cr_2O_3 + 2Al \rightarrow Al_2O_3 + 2Cr$

When limestone is heated,$CO_{2}$ is given off. The metallurgical operation is

Consider the following statements:
Roasting is carried out to:
$(i)$ convert sulphide to oxide and sulphate
$(ii)$ remove water of hydration
$(iii)$ melt the ore
$(iv)$ remove arsenic and sulphur impurities
Of these statements: