Question

Identify the reactions that occur in photochemical smog.
(i) $CH _{2}= O + H _{2} \longrightarrow CH _{3} OH$
(ii) $NO _{2}(g) \stackrel{h v}{\longrightarrow } NO (g)+ O (g) ; O (g)+ O _{2}(g) \longrightarrow O _{3}(g)$
(iii) $3 CH _{4}+2 O _{3} \longrightarrow 3 CH _{2}= O +3 H _{2} O$
(iv) $NO (g)+ O _{3}(g) \longrightarrow NO _{2}(g)+ O _{2}(g)$

• A. (ii), (iii), (iv)
• B. (i), (ii), (iii)
• C. (i), (ii), (iv)
• D. (i), (iii), (iv)

Answer 1

Answer: (A)

Formation of $NO , O _{3}, NO _{2}$ and $CH _{2} O$ occur in photochemical smog. Photochemical smog is a type of air pollution due to reaction of solar radiation with airborne pollutant mixtures of nitrogen oxides (NO) and organic compounds (hydrocarbon).

Therefore, oxidation and reduction reactions found in photochemical smog.

Thus, option (a) (ii), (iii) and (iv) is correct.