The formation of the ozone layer

1. The formation of the ozone layer The formation of the ozone in the stratosphere region begins with the photodissociation of oxygen molecules by the solar radiation at . wavelengths below 240 nm O 2 O + O The highly reactive O atoms combine with oxygen molecules to form ozone as follows : O 3 + M O + O 2 + M M : Some inert substance. The role of M in this exothermic reaction is to absorb some of the excess energy released and prevent the spontaneous decomposition of the O 3 . molecule O 3 O + O 2 UV < 240 nm UV

2. Some physical properties of ozone Pure ozone is a blue gas with a strong irritating smell. It is more soluble than oxygen in water. It gets liquefied to a deep blue color liquid, when cooled in liquid air. It boils at 161 K and solidifies to violet-black crystals, which melts at 81 K.

3. Some chemical properties of ozone Decomposition: Ozone is unstable compound. Pure ozone decompose instantaneously at 573 K. 2O 3 3O 2 Oxidizing property : Ozone acts as a powerful oxidizing agent due to the reaction : O 3 O 2 + O Reducing property : Ozone reduces peroxides to oxides and in turn gets reduced to oxygen H 2 O 2 + O 3 H 2 O + 2O 2 573 K