Match List - I with List - II.

Choose the correfct answer from the options given below.

The correct option is (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii).

Let us analyze the chemical reactions given in List - I and match them with the atmospheric phenomena in List - II:

(a) $2{\mathrm{SO}}_2\left(g\right)+O_2\left(g\right)\to 2{\mathrm{SO}}_3\left(g\right)$ matches with (iv) Tropospheric pollution:
The oxidation of sulfur dioxide (${\mathrm{SO}}_2$) to sulfur trioxide (${\mathrm{SO}}_3$) in the presence of oxygen is a key chemical reaction occurring in the troposphere. It contributes significantly to tropospheric pollution and the subsequent formation of acid rain.

(b) $\mathrm{HOCl}\left(g\right)\stackrel{h\nu }{\to }\stackrel{·}{\mathrm{OH}}+\stackrel{·}{\mathrm{Cl}}$ matches with (iii) Ozone depletion:
Hypochlorous acid ($\mathrm{HOCl}$) acts as a reservoir molecule for chlorine in the stratosphere. Under the action of sunlight ($h\nu$), it undergoes photolysis to release highly reactive hydroxyl ($\stackrel{·}{\mathrm{OH}}$) and chlorine ($\stackrel{·}{\mathrm{Cl}}$) free radicals. The chlorine radical ($\stackrel{·}{\mathrm{Cl}}$) initiates catalytic cycles that destroy stratospheric ozone ($O_3$).

(c) ${\mathrm{CaCO}}_3+H_2{\mathrm{SO}}_4\to {\mathrm{CaSO}}_4+H_{2}O+{\mathrm{CO}}_2$ matches with (i) Acid rain:
This reaction represents the damaging effect of acid rain (containing sulfuric acid, $H_2{\mathrm{SO}}_4$) on monuments and buildings made of marble or limestone (calcium carbonate, ${\mathrm{CaCO}}_3$).

(d) ${\mathrm{NO}}_2\left(g\right)\stackrel{h\nu }{\to }\mathrm{NO}\left(g\right)+O\left(g\right)$ matches with (ii) Smog:
The photolysis of nitrogen dioxide (${\mathrm{NO}}_2$) by solar radiation yields nitric oxide ($\mathrm{NO}$) and atomic oxygen ($O$). This atomic oxygen rapidly reacts with molecular oxygen ($O_2$) to produce ground-level ozone ($O_3$), which is a primary constituent of photochemical smog.