Question

Give the reaction involved during extraction of zinc from its ore by
(a) roasting of zinc ore.`" "`(b) calcination of zinc ore. 

Answer 1

 Roasting of zinc ore Roasting is done for the sulphide ore. Sulphide ore of zinc is ZnS (zinc blende) 
`underset(("zinc blende ore")) underset("Zinc sulphide")(2ZnS(s))+underset(("from air"))underset("Oxygen")(3O_(2))overset("Roasting")tounderset("Zinc metal")(Zn(s))+2SO_(2)(g)`
Zinc sulphide Oxygen Zinc oxide (zinc blende ore) (from air)
`underset("Zinc oxide")(ZnO(s))+underset("Carbon(reducing agent)")(C(s))overset(Delta)tounderset("Zinc metal")(ZnO(s))+underset("Carbon monoxide")(CO(g))`
(b) Caicination of zinc ore Caloination is done for the carbonate ore. Carbonate ore of Zn is caiamine `ZnCO_(3)`.
`underset("Zinc carbonate")(ZnCO_(3)(s))overset("Calcination")tounderset("Zinc oxide")(ZnI(s))+underset("Carbon dioxide")(CO(g)uparrow)`
ZnO is then reduced to zinc by heating with coke (carbon).
`underset("Zinc oxide")(ZnO(s))+underset("Carbon")(C(s))overset(Delta)tounderset("Zinc metal")(Zn(s))+underset("Carbon monoxide")(CO(g))`