Question

Consider two chemical reactions (A) and (B) that take place during metallurgical process :

(A) ZnCO_3(s) + △ →  ZnO_(s) + CO_2(g) 

(B) 2 ZnS_(s) + 3O_2(g) + △ → 2 ZnO_(s) + 2SO_2(g)

The correct option of names given to them respectively is : 

(1) (A) is calcination and (B) is roasting 

(2) Both (A) and (B) are producing same product so both are roasting 

(3) Both (A) and (B) are producing same product so both are calcination 

(4) (A) is roasting and (B) is calcination

Answer 1

Answer is (A) ZnCO_3(s) + △ →  ZnO_(s) + CO_2(g) 

Heating in absence of oxygen in calcination. 

(B) 2Zns(s) + 3O₂(g) →  2ZnO(g) + 2SO₂(g) 

heating in presence of oxygen in roasting 

Hence (A) is calcination while