Question: The pair that does NOT require calcination is:
$\mathrm{ZnO}$ and $\mathrm{MgO}$
$\mathrm{Fe}_{2} \mathrm{O}_{3}$ and $\mathrm{CaCO}_{3} \cdot \mathrm{MgCO}_{3}$
$\mathrm{ZnO}$ and $\mathrm{Fe}_{2} \mathrm{O}_{3} \cdot \mathrm{xH}_{2} \mathrm{O}$
$\mathrm{ZnCO}_{3}$ and $\mathrm{CaO}$
Correct Option: 1
Solution:
$\mathrm{ZnO} \& \mathrm{MgO}$ both are in oxide form therefore no change on calcination.
