Which of the following statements about the d | vedclass

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(B) Freons and chlorofluorocarbons reach the stratosphere without being destroyed in the troposphere due to their low reactivity. In the stratosphere,

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The problem of ozone depletion is more serious at poles because ice crystals in the clouds over poles act as catalyst for photochemical reactions involving the decomposition of ozone by $Cl^{\bullet}$ and $ClO^{\bullet}$ radicals.

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(B) Freons and chlorofluorocarbons reach the stratosphere without being destroyed in the troposphere due to their low reactivity. In the stratosphere,the $Cl$ and $Br$ atoms are liberated from the parent compound by the action of ultraviolet light. For example: $CF_2Cl_2 + h
u 	o CF_2Cl^{\bullet} + Cl^{\bullet}$ $CFCl_3 + h
u 	o CFCl_2^{\bullet} + Cl^{\bullet}$ The $Cl^{\bullet}$ atoms destroy ozone molecules through catalytic cycles. The problem is more serious at the poles because ice crystals in polar stratospheric clouds provide a surface for these reactions to occur more efficiently.

Which of the following statements about the depletion of ozone layer is correct?

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