Question

The statement that is not true about ozone is :

(1) in the stratosphere, CFCs release chlorine free radicals $\require{mhchem}\ce{(Cl)}$ which reacts with $\ce{O3}$ to give chlorine dioxide radicals.

(2) in the stratosphere, it forms a protective shield against UV radiation.

(3) it is a toxic gas and its reaction with $\ce{NO}$ gives $\ce{NO2}$

(4) in the atmosphere, it is depleted by CFCs.

Comments

The p block elements

Answer 1

Ans. (1) in the stratosphere, CFCs release chlorine free radicals (Cl) which reacts with O3 to give chlorine dioxide radicals.

Sol. In presence of sunlight CFC’s molecule divides & release chlorine free radical, which react with ozone give chlorine monoxide radical ( ClO ) and oxygen.  

$\require{mhchem}\ce{CF2Cl2(g)->[UV] Cl(g) + FC2Cl (g) }$

$\ce{Cl(g) + O3(g) -> ClO(g) + O2(g)}$

$\ce{ClO(g) + O(g) -> Cl(g) + O2(g)}$

Comments

option 1 is wrong 

as during reaction ClO* and Cl* is formed not ClO₂