JEE Main · 2023 · 13 Apr 2023 · Shift 1 · Environmental Chemistry

The radical which mainly causes ozone depletion in the presence of UV radiations is:

(A) $CH_{3}^{∙}$
(B) $NO^{∙}$
(C) $Cl^{∙}$ ✓ Correct
(D) $\dot{O} H$

Answer: (C)

Solution

Chlorine radicals (Cl•) are the primary cause of ozone depletion. CFCs (chlorofluorocarbons) release Cl• radicals upon UV irradiation. The mechanism is: CF₂Cl₂ + UV → Cl• + •CF₂Cl, then Cl• + O₃ → ClO• + O₂, and ClO• + O → Cl• + O₂. The Cl• radical is regenerated and acts as a catalyst, destroying many ozone molecules in a chain reaction.

JEE Main · 2023 · 13 Apr 2023 · Shift 1 · Single correct option

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