JEE Main 2023 — Environmental Chemistry Question with Solution

Chlorofluorocarbon compounds (CFCs) are non-reactive, non-flammable molecules that are used in refrigerators, air conditioners, plastics, and electronic industries. Once released CFCs mix with atmospheric gases and reach the stratosphere, where they are decomposed by UV radiations.

${\mathrm{CF}}_2{\mathrm{Cl}}_2\left(\mathrm{g}\right)\stackrel{\mathrm{uv}}{\to }\stackrel{\odot }{\mathrm{Cl}}\left(\mathrm{g}\right)+\stackrel{\odot }{\mathrm{C}}{\mathrm{F}}_2\mathrm{Cl}\left(\mathrm{g}\right)$

The chlorine radical released will react with ozone.

$\stackrel{\odot }{\mathrm{Cl}}\left(\mathrm{g}\right)+{\mathrm{O}}_3\left(\mathrm{g}\right)\stackrel{}{\to }{\mathrm{O}}_2\left(\mathrm{g}\right)+\stackrel{\odot }{\mathrm{ClO}\left(\mathrm{g}\right)}$

The $\stackrel{\odot }{\mathrm{Cl}}\mathrm{O}$ will generate chlorine radicals again

$\stackrel{\odot }{\mathrm{ClO}\left(\mathrm{g}\right)}+\mathrm{O}\left(\mathrm{g}\right)\stackrel{}{\to }{\mathrm{O}}_2\left(\mathrm{g}\right)+\stackrel{\odot }{\mathrm{Cl}}$