Explain the following in detail.
Ozone depletion.

Explanation

Ozone layer is depleted by the pollutant gases such as chlorofluorocarbons, `NO_2` and HOCl.
The chlorofluorocarbons, break down in the presence of sunlight and deplete the ozone layer as Follows.
`{:(CF_2Cl_2overset(UV)to dotCl+dotCF_2Cl),(dotCl+O_3 to CldotO+O_2),(CldotO+O todotCl+O_2):}`
The chlorine radicals are continuously regenerated and cause the breakdown of ozone. One CFC molecule destroys one lakh `O_3` Molecules.
In winter season the ClO reacts with `NO_2` forming chlorine nitrate. This hydrolyses giving hypochlorous acid HCl . In summer season these break up providing Cl radicals which can deplete the ozone layer.
Effects caused by ozone layer depletion : Due to depletion of ozone layer the UV light coming from the sun directly reaches the earth and effects the life on the earth.
The UV radiations cause ageing of skin, cataract, sunburns, skin cancer, killing of phytoplanktons, damage the fish production etc.
It increases the evaporation of surface water and decrease the moisture content of the soil.