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प्रश्न
State the chemicals responsible for ozone layer destruction.
उत्तर
Chemicals responsible for the destruction of the ozone layer:
(1) Excessive use of CFCs:
CFCs enter the atmosphere because of their excessive use in solvents, aerosol sprays, propellants, refrigerants and blowing agents for plastic foams.
CFCs are decomposed by UV rays to highly reactive chlorine which is produced in the atomic form.
CF2Cl2(g) → CF2Cl(g) + Cl(g)
This free radical [Cl] reacts with ozone, and chlorine monoxide is formed.
Cl(g) + O3(g) → ClO(g) + O2(g)
This causes depletion of ozone, and chlorine monoxide further reacts with atomic oxygen to produce more free radicals of chlorine.
ClO(g) + O(g) → Cl(g) + O2(g)
Again this free radical [Cl] destroys ozone, and the process continues giving rise to large-scale ozone depletion.
(2) The fuel of planes:
When the fuel of planes burns, a large quantity of nitric oxide and other gases is emitted in the atmosphere. Nitric oxide reacts with ozone to form nitrogen dioxide and nitrogen trioxide.
NO(g) + O3(g) → NO2(g) + O2(g)
NO2(g) + O3(g) → NO3(g) + O2(g)
This also causes depletion of ozone.
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संबंधित प्रश्न
Which pollutant released into the air during refrigeration and airconditioning is the greatest contributor to the depletion of ozone layer?
(a) BHC
(b) DDT
(c) CFC
(d) UNEP
The excessive exposure of humans to ultraviolet rays results in:
- damage to immune system
- damage to lungs
- skin cancer
- peptic ulcers
O2 is converted into O3 by the action of :
(a) infrared radiations
(b) ultraviolet radiations
(c) gamma radiations
(d) cosmic radiations
“Damage to the ozone layer is a cause of concern”. Justify this statement.
Name the following pollutants:
Any two chemicals leading to the formation of ozone holes.
Discuss in detail the process of ozone depletion.
Select the correct answer from the following statement:
The gas which in presence of U.V. light gives two atoms of the same gas.
Select the correct answer from the following statement:
A chemical responsible for ozone depletion.
A motor car, with its glass totally closed, is parked directly under the sun. The inside temperature of the car rises very high. Explain why?
What is exactly measured in Dobson units or DU?
