Chemistry - Complete s-block Question with Solution | TestHub

(D) is not correctly represented.

Magnesium is not amphoteric in the usual school-level comparison and does not give the stated reaction with $\mathrm{NaOH}$

$\mathrm{N}{\mathrm{a}}_2\mathrm{Mg}{\mathrm{O}}_2$ is not formed under these conditions.

(A) is acid displacement of hydrogen.

(B) represents dissolution of $\mathrm{Mg}(\mathrm{OH}{)}_2$ in $\mathrm{N}{\mathrm{H}}_4\mathrm{Cl}$.

The $\mathrm{N}{\mathrm{H}}_4^{+}$ ion consumes $\mathrm{O}{\mathrm{H}}^{-}$ and shifts the dissolution equilibrium.

(C) represents nitride formation when ammonia passes over heated magnesium.