Question: The reaction that does NOT define calcination is:-
$\mathrm{ZnCO}_{3} \stackrel{\Delta}{\longrightarrow} \mathrm{ZnO}+\mathrm{CO}_{2}$
$\mathrm{Fe}_{2} \mathrm{O}_{3} \cdot \mathrm{XH}_{2} \mathrm{O} \stackrel{\Delta}{\longrightarrow} \mathrm{Fe}_{2} \mathrm{O}_{3}+\mathrm{XH}_{2} \mathrm{O}$
$\mathrm{CaCO}_{3} \cdot \mathrm{MgCO}_{3} \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}+\mathrm{MgO}+2 \mathrm{CO}_{2}$
$2 \mathrm{Cu}_{2} \mathrm{~S}+3 \mathrm{O}_{2} \stackrel{\Delta}{\longrightarrow} 2 \mathrm{Cu}_{2} \mathrm{O}+2 \mathrm{SO}_{2}$
Correct Option: , 4
Solution:
Calcination in carried out for carbonates and oxide ores in absence of oxygen. Roasting is carried out mainly for sulphide ores in presence of excess of oxygen.
