Formation of photochemical smog involves the following reaction in which $\mathrm{A}$, $\mathrm{B}$ and $\mathrm{C}$ are respectively. (i) $\mathrm{NO}_{2} \xrightarrow{h\nu} \mathrm{A}+\mathrm{B}$ (ii) $\mathrm{B}+\mathrm{O}_{2} \rightarrow \mathrm{C}$ (iii) $\mathrm{A}+\mathrm{C} \rightarrow \mathrm{NO}_{2}+\mathrm{O}_{2}$ Choose the correct answer from the options given below:

(D) $\mathrm{NO}, \mathrm{O} \& \mathrm{O}_{3}$

(A) $\mathrm{O}, \mathrm{NO} \& \mathrm{NO}_{3}^{-}$

(B) $\mathrm{O}, \mathrm{N}_{2} \mathrm{O} \& \mathrm{NO}$

(C) $\mathrm{N}, \mathrm{O}_{2} \& \mathrm{O}_{3}$

JEE Main · 2023 · 30 Jan 2023 · Shift 1 · Environmental Chemistry

Formation of photochemical smog involves the following reaction in which

A

B

and

C

are respectively.
(i)

NO_{2} h ν A + B

(ii)

B + O_{2} \to C

(iii)

A + C \to NO_{2} + O_{2}

Choose the correct answer from the options given below:

Answer: (D)

When nitrogen dioxide absorbs sunlight it undergoes photodissociation,

N O_{2} h ν NO + O

, so

A

is nitric oxide

NO

and

B

is the reactive oxygen atom

O

. This oxygen atom adds to molecular oxygen,

O + O_{2} \to O_{3}

, giving

C

as ozone

O_{3}

. The third step

NO + O_{3} \to N O_{2} + O_{2}

regenerates

N O_{2}

and completes the cycle responsible for photochemical smog. Hence

A

B

and

C

are

NO

O

and

O_{3}

respectively.

JEE Main · 2023 · 30 Jan 2023 · Shift 1 · Single correct option