An inorganic white crystalline compound (A) has a rock salt structure. (A) on reaction with cone. ${\mathrm{H}}_2{\mathrm{SO}}_4$ and ${\mathrm{MnO}}_2$ , evolves a pungent smelling, greenish-yellow gas (B). Compound (A) gives white ppt. of (C) with ${\mathrm{AgNO}}_3$ solution. Compounds (A), (B) and (C) will be respectively:

$\mathrm{NaC}1$, a white crystalline solid with a rock salt crystal structure, is Compound A. B is ${\mathrm{Cl}}_2$, a gas with a strong scent and a greenish hue.  ${\mathrm{AgNO}}_3$ and $\mathrm{NaC}1$ interact, resulting in the formation of a white, milky precipitate of $\mathrm{NaC}1$.

$\begin{array}{l}2\mathrm{NaCl}+2{\mathrm{H}}_2{\mathrm{SO}}_4+{\mathrm{MnO}}_2\to {\mathrm{Na}}_2{\mathrm{SO}}_4+{\mathrm{MnSO}}_4+2{\mathrm{H}}_2\mathrm{O}+{\mathrm{Cl}}_2\\ {\mathrm{AgNO}}_3+\mathrm{NaCl}\to {\mathrm{NaNO}}_3+\mathrm{AgCl}\end{array}$