Question

Pollutants present in the photochemical smog is/are :

• A. Peroxyacetyl nitrate
• B. Ozone
• C. Sulphur dioxide
• D. Nitrogen dioxide

Answer 1

Answer: (A), (B), (D)

Nitrogen dioxide

Photochemical smog formed by action of sunlight on unsaturated hydrocarbons and nitrogen oxides.
Nitrogen oxides split into nitric oxide and nascent oxygen.
$N{O}_2\left(g\right)\stackrel{h\nu }{\to }NO\left(g\right)+O\left(g\right)$
Then $O_2$ forms ozone.
$O\left(g\right)+O_2\left(g\right)\rightleftharpoons O_3\left(g\right)$
This $O_3$ reacts with $C{H}_4$ to give PAN
$C{H}_4+O_3\to \underset{\text{PAN(Peroxyacetyl nitrate)}}{3C{H}_3\underset{\underset{O}{|}|}{C}OON{O}_2}$
So, photochemical smog contains $O_3,N{O}_2,$ PAN.
Hence, the correct answer will be option (d).