What are the reactions involved for ozone layer depletion in the stratosphere?

Asked by Abhisek | 1 year ago |  65

1 Answer

Solution :-

In the stratosphere, ozone is actually formed by the action of UV rays on Dioxygen molecules(O2).

(i)  \( O_{2(g)} \overset{UV}{\rightarrow}(g) +O_(g)\)

 

(ii)  \( O_{2(g)} + O_(g) \overset{UV}{\leftrightarrow} O_{3(g)}\)

The second reaction shows that there is a dynamic equilibrium between the decomposition and production of ozone molecules. Any factor that disturbs this equilibrium may lead to the ozone layer getting depleted due to its decomposition. One such example of these factors is the chlorofluorocarbon compounds (CFCs). These are non-flammable and non-reactive molecules that find usage in air conditioners, refrigerators, plastics, and electronic industries.

Once it is released into the atmosphere, these CFCs get mixed with atmospheric gases and then, reach the stratosphere, where they get decomposed due to reactions with UV radiations.

 

(iii) )\( CF_2Cl_2\overset{UV}{\rightarrow} \dot{C}l(g) + \dot{C}F_2Cl _(g)\)

The chlorine free radical which is produced in the third reaction reacts with ozone as shown below:

 

(iv) \( \dot{C}_(g) + O_{3(g)} \rightarrow→ Cl\dot{O}_(g) + O_{2(g)}\)

And, \( Cl\dot{O}_(g) + O_(g) \rightarrow→ \dot{C}l_(g) + O_{2(g)}\)

The radicals, on further reaction with atomic oxygen, resulting in the production of more chlorine radicals.

This regeneration of chlorine-free radicals results in a continuous breakdown of ozone in the stratosphere, thus almost permanently damaging the ozone layer.

Answered by Pragya Singh | 1 year ago

Related Questions

For your agricultural field or garden you have developed a compost producing pit. Discuss the process in the light of bad odour, flies and recycling of wastes for a good product.

Class 11 Chemistry Environmental Chemistry View Answer

A large number of fish are suddenly found floating dead on a lake. There is no evidence of toxic dumping but you find an abundance of phytoplankton. Suggest a reason for the fish kill.

Class 11 Chemistry Environmental Chemistry View Answer

What would have happened if the greenhouse gases were totally missing in the earth’s atmosphere? Discuss.

Class 11 Chemistry Environmental Chemistry View Answer

What do you mean by green chemistry? How will it help decrease environmental pollution?

Class 11 Chemistry Environmental Chemistry View Answer