Chemistry - Metallurgy Question with Solution | TestHub

$\mathrm{ }{\mathrm{ZnCO}}_3\to \mathrm{ZnO}+{\mathrm{CO}}_2$, It shows the calcination process, Heating of hydrated and carbonated ore in the absence of the air then metal oxide will form.

${\mathrm{Fe}}_2{\mathrm{O}}_3+3\mathrm{C}\to 2\mathrm{Fe}+3\mathrm{CO}$, This is the smelting process. In this process reduction of metal oxide in the presence of the suitable reducing agent like $\mathrm{C}$ and $\mathrm{CO}$ to get the metal oxide. 

$\mathrm{ }2\mathrm{PbS}+3{\mathrm{O}}_2\to 2\mathrm{PbO}+2{\mathrm{SO}}_2$, This is the roasting process. In this process, heating of the sulphide ores in the presence of the air to obtain the metal oxide.

$\mathrm{ }{\mathrm{Al}}_2{\mathrm{O}}_3·2{\mathrm{H}}_2\mathrm{O}\to {\mathrm{Al}}_2{\mathrm{O}}_3+2{\mathrm{H}}_2\mathrm{O},$ This is the calcination process.