JEE Main · 2021 · 26 Feb 2021 · Shift 1 · Environmental Chemistry

The presence of ozone in troposphere :

(A)generates photochemical smog✓ Correct
(B)Protects us from the $X$ - ray radiation
(C)protects us from the UV radiation
(D)protects us from greenhouse effect

Answer: (A)

Solution

The ozone that screens ultraviolet radiation lies in the stratosphere. In the troposphere ozone is itself a pollutant and a secondary one: nitrogen dioxide from vehicle exhaust absorbs sunlight and splits into nitric oxide and an oxygen atom, and that atom combines with

O_{2}

to build ozone close to the ground.

N O_{2} h ν NO + O, O + O_{2} \to O_{3}

This ozone then attacks unburnt hydrocarbons to give aldehydes and peroxyacetyl nitrate, the eye irritants of a brown photochemical haze.
Ozone present in the troposphere therefore generates photochemical smog.

JEE Main · 2021 · 26 Feb 2021 · Shift 1 · Single correct option

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JEE Main · 2021 · 26 Feb 2021 · Shift 1 · Environmental Chemistry

Solution

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