Question

Photochemical smog consists of excessive amounts of X in addition to aldehydes, ketones, PAN etc. X is

• A. Methane
• B. Carbon monoxide
• C. Carbon dioxide
• D. Ozone

Answer 1

The correct option is D

Ozone

The explanation for the correct answer:

Photochemical smog:-

1. It is basically a type of smog which is produced when the UV rays directly from the sun will interact with the oxides of nitrogen.
2. It is generally formed by a complex series of chemical reactions which will involve sunlight, oxides of nitrogen, volatile organic compounds, aldehydes, ketones, PAN and Ozone which is present there in the atmosphere.
3. Reactions involved:-

$\underset{\mathrm{Nitrogen}\mathrm{dioxide}}{{\mathrm{NO}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{hv}}{\to }\underset{\mathrm{Nitrogen}\mathrm{oxide}}{\mathrm{NO}\left(\mathrm{g}\right)}+\mathrm{O}\left(\mathrm{g}\right)$

$\mathrm{O}\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\leftrightarrow {\mathrm{O}}_3\left(\mathrm{g}\right)$

${\mathrm{O}}_3\left(\mathrm{g}\right)+\mathrm{NO}\left(\mathrm{g}\right)\to {\mathrm{NO}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$

$3{\mathrm{CH}}_4\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to \underset{\mathrm{Formaldehyde}}{3{\mathrm{CH}}_2=\mathrm{O}\left(\mathrm{g}\right)}+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Therefore, the correct answer is (D):- Ozone.