Question

Chlorofluorocarbons $\left(CFC{l}_3\right)$ and fluorocarbons $\left(C_x{F}_y\right)$ are effective scavengers for ozone due to :

• A. photolytic reaction of $O_2$ producing $Cl$ radicals
• B. photolytic decomposition of $O_3$ producing $O$ radicals
• C. photolytic decomposition of $O_3$ by $Cl$ radicals into $O_2$
• D. photolytic production of oxides of nitrogen

Answer 1

The correct option is C photolytic decomposition of $O_3$ by $Cl$ radicals into $O_2$

$CFCs$ absorb $UV$ radiation in stratosphere and liberate chlorine atoms which in turn destroy ozone layer.

$CFC{l}_3\underset{UV}{\overset{hv}{\to }}CFC{l}_2^{\ast }+C{l}^{\ast }$

$C{l}^{\ast }+O_3\to Cl{O}^{\ast }+O_2$

$Cl{O}^{\ast }+\left(O\right)\to C{l}^{\ast }+O_2$