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

Options

A. The problem of ozone depletion is less serious at poles because `NO_2` solidifies and is not available for
consuming `ClO^(**)` radicals.
B. 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^(**)` and `ClO^(**)` radicals.
C. Freons, chlorofluorocarbons, are inert chemically, they do not react with ozone in stratosphere.
D. Oxides of nitrogen also do not react with ozone in stratosphere.

Answer

B

Explanation

`CFCl_3 + "UV light"to CFCl_2 + Cl^(dot)`
`Cl^(dot) +O_3 to ClO+O_2 , ClO+dotO to dotCl + O_2`
Reaction without polar stratospheric clouds : `CFCl_3 + "UV light" to Cl^(dot) +CFCl_2`
`Cl^(dot) + O_3 to ClO+ O_2 , ClO+NO_2 to ClONO_2` (Reservoirs)
With polar stratospheric clouds :

The main reason for ozone depletion in polar regions is that ice crystals catalyze ozone depletion reaction.