Question

Write the chemical equation for the formation of ozone in the atmosphere.

Answer 1

• Ozone is an allotropic form of oxygen found in the upper layer of the atmosphere about 20 Km away from the surface of earth.
• It is formed from the oxygen in the presence of sunlight.It protects earth’s surface from harmful UV-radiations.

Step 1

• When UV rays interact with dioxygen molecule (${\mathrm{O}}_2$), it get split up into free oxygen atoms ($\mathrm{O}$).

$\underset{\mathrm{oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\stackrel{UV}{\to }\underset{freeoxygenatom}{O\left(g\right)}+\underset{freeoxygenatom}{O\left(g\right)}$

Step 2

• This free oxygen combine with molecular oxygen to give ozone.

$\underset{\mathrm{free}\mathrm{oxygen}\mathrm{atom}}{\mathrm{O}\left(\mathrm{g}\right)}+\underset{\mathrm{dioxygen}\mathrm{molecule}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{UV}}{\rightleftharpoons }\underset{\mathrm{ozone}}{{\mathrm{O}}_3\left(\mathrm{g}\right)}$