# The pair that does NOT require calcination is:

Question:

The pair that does NOT require calcination is:

1. $\mathrm{ZnO}$ and $\mathrm{MgO}$

2. $\mathrm{Fe}_{2} \mathrm{O}_{3}$ and $\mathrm{CaCO}_{3} \cdot \mathrm{MgCO}_{3}$

3. $\mathrm{ZnO}$ and $\mathrm{Fe}_{2} \mathrm{O}_{3} \cdot \mathrm{xH}_{2} \mathrm{O}$

4. $\mathrm{ZnCO}_{3}$ and $\mathrm{CaO}$

Correct Option: 1

Solution:

$\mathrm{ZnO} \& \mathrm{MgO}$ both are in oxide form therefore no change on calcination.