Match List - I with List - II and choose the correct answer

Correct Answer: (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)

To match each chemical reaction in List - I with its corresponding atmospheric effect or phenomenon in List - II, let us analyze the reactions visible in the provided image step-by-step:

1. Item (a):

$2{\text{SO}}_2(\text{g})+{\text{O}}_2(\text{g})\to 2{\text{SO}}_3(\text{g})$

The oxidation of sulfur dioxide (${\text{SO}}_2$) to sulfur trioxide (${\text{SO}}_3$) occurs in the lower atmosphere (troposphere), where atmospheric pollutants like ${\text{SO}}_2$ lead to Tropospheric pollution.
Therefore, (a) matches with (iv).

2. Item (b):

$\text{HOCl}(\text{g})\stackrel{h\nu }{\to }\stackrel{·}{\text{O}}\text{H}+\stackrel{·}{\text{C}}\text{l}$

Under sunlight ($h\nu$), hypochlorous acid ($\text{HOCl}$) breaks down into free radicals ($\stackrel{·}{\text{O}}\text{H}$ and $\stackrel{·}{\text{C}}\text{l}$). These chlorine free radicals react with ozone molecules in the stratosphere, causing Ozone depletion.
Therefore, (b) matches with (iii).

3. Item (c):

${\text{CaCO}}_3+{\text{H}}_2{\text{SO}}_4\to {\text{CaSO}}_4+{\text{H}}_2\text{O}+{\text{CO}}_2$

Calcium carbonate (${\text{CaCO}}_3$), commonly found in marble structures, reacts with sulfuric acid (${\text{H}}_2{\text{SO}}_4$ present in acid precipitation). This is a direct consequence and characteristic reaction of Acid rain damaging marble monuments.
Therefore, (c) matches with (i).

4. Item (d):

${\text{NO}}_2(\text{g})\stackrel{h\nu }{\to }\text{NO}(\text{g})+\text{O}(\text{g})$

Photolysis of nitrogen dioxide (${\text{NO}}_2$) by solar radiation produces nitric oxide ($\text{NO}$) and reactive oxygen atoms ($\text{O}$), which initiates the chemical chain reactions leading to the formation of photochemical Smog.
Therefore, (d) matches with (ii).

Comparing these pairs with the given options:

(a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)