Question

Differentiate between roasting and vaccination.explain the two with the help of suitable chemical equations

Answer 1

 To begin with, Calcination and roasting both involve heating but the only difference is , roasting is done in the presence of air while calcination is done in the absence of air.

EG: CALCINATION: ZnCO3 on (heating)----------- ZNO + CO2

ZNO + C (Coke- a form of carbon) (on heating) --------------- ZN + CO

ROASTING : ZnS + O2 ------------- ZnO + SO2

ZnO + C ------------ Zn + CO

 

 

roasting is done in excess supply of air

calcination is done in limited supply of air