Tag: ozone and its depletion

Questions Related to ozone and its depletion

The proposal to ban supersonic jet planes in
Russia is because
A) They travel with very high speed.
B) It is dangerous to travel in them.
C) Their exhaust gases react with ozone.

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. A & B

  2. B

  3. C

  4. A, B & C

Show answer
Correct Option: C
Explanation:

The proposal to ban supersonic jet planes in Russia is because of toxic gases which reacts with ozone layer and damage it.

Result of ozone hole is:

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. green house effect

  2. global warning

  3. acid rain

  4. UV rays reach the earth

Show answer
Correct Option: D
Explanation:
The depletion of ozone layer is due to the increase in emissions of chlorine and bromine-contained  compounds like CFC's, methyl chloroform and methyl bromide.
Emissions of green gases affects ozone by atmospheric interaction.
As a result, U.V. rays reach the earth's atmosphere and causes skin cancer, and damages living and non-living things.

Which of the following statement is wrong?

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. Ozone is not responsible for green house effect

  2. Ozone can oxidise sulphur dioxide present in the atmosphere to sulphur trioxide

  3. Ozone hole is thinning of ozone layer present in stratosphere

  4. Ozone is produced in upper stratosphere by the action of UV rays on oxygem

Show answer
Correct Option: A
Explanation:

Ozone is a greenhouse gas that absorbs and emits radiant energy within thermal infrared range. The increase in ozone in the troposphere because of surface pollution gases have increased the warming effect on the earth's surface and contributed to a greenhouse effect.

In the upper layers of atmosphere, ozone is formed ?

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. By action of electric discharge on oxygen molecules

  2. By action of ultraviolet rays on oxygen molecules

  3. By action of infrared rays on oxygen molecules

  4. Due to sudden drop of pressure

Show answer
Correct Option: B
Explanation:
  • In the upper layer of atmosphere, the Ultraviolet rays (UV rays) split the molecule of oxygen $(O _2)$ into its constituent 2 atoms.
  • Each of the atom then combine with another oxygen $(O _2)$ molecule which gives rise to Ozone$(O _3)$.
  • Hence option B is correct answer.

Assertion : Ozone is destroyed by CFCs in the upper stratosphere

Reason : Ozone holes increase the amount of UV radiation reaching the earth.

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. Assertion and reason are correct , but the reasons is not the explanation for the assertion

  2. Assertion is false, but the reason is correct

  3. Assertion and reason are incorrect, Assertion and reason are both correct

  4. And the reason is the correct explanation for the assertion

Show answer
Correct Option: A
Explanation:
The upper stratosphere consists of ozone $(O _3)$, which protect us from harmful ultraviolet (UV) radiations coming from the sun.
When CFC reacts with ozone it breaks the molecule of ozone resulting in ozone layer depletion.

A considerable part of the harmful $UV$ rays of the sum does not reach the surface of the earth. This is because high above the earth's atmosphere, there is a layer of___________.

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. $O _3$

  2. $CO _2$

  3. $SO _2$

  4. $NO$

Show answer
Correct Option: A
Explanation:

This is because of ozone layer.Ozone is a gas in the atmosphere that protects everything living on the Earth from harmful ultraviolet (UV) rays from the Sun.The ozone layer absorbs ultraviolet (UV) radiation from the sun, preventing most of it from reaching the earth's surface. 

The absorption of $UV$ radiation by $O _3$:

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. protects the inhabitants of our planet from injurious radiation

  2. maintains an equilibrium between the concentrations of $O _2$ and $O _3$

  3. makes both the function A and B above effective

  4. makes no function effective

Show answer
Correct Option: C
Explanation:

We know that, UV-B radiation is very harmful. 


The UV light will also destroy ozone and break ozone back down into atomic oxygen (O) and diatomic oxygen ($O _2$) Therefore, the ozone layer does a great job filtering UV radiation and this process protects the inhabitants of our planet from injuries radiation and adsorption of UV radiation has maintained the equilibrium between the con. of oxygen and ozone in the atmosphere.


So, A and B are both effective 

C is the correct answer.

Ozone layer is being depleted. This is due to :

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. NO (Nitrogen oxide) emission from supersonic jets

  2. Chlorofluorocarbon used as aerosols

  3. Both (a) and (b)

  4. None of the above

Show answer
Correct Option: C
Explanation:

Chlorofluorocarbons (CFCs) and other halogenated ozone-depleting substances (ODS) are mainly responsible for ozone depletion.


Depletion of the ozone layer is likely to aggravate existing health effects caused by exposure to UV radiation, as stratospheric ozone is a particularly effective UV radiation absorber. As the ozone layer becomes thinner, the protective filter provided by the atmosphere is progressively reduced. 

Consequently, human beings and the environment are exposed to higher UV radiation levels, and especially higher UV levels that have the greatest impact on human health, animals, marine organisms and plant life.


Hence, option C is correct.

State True or False.
The main function of ozone is to absorb sun's UV radiations, hence protecting the Earth from its harmful effects.

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
True.
The main function of ozone is to absorb Sun's UV radiations, hence protecting the Earth from its harmful effects. The function of the ozone layer is to shield the earth from the harmful ultraviolet rays of the sun and to keep the Earth warm.

Which of the following chemicals is responsible for ozone layer destruction?

zoology allotropy of oxygen ozone - a case study stratospheric pollution ozone and its depletion

  1. Chlorofluorocarbons

  2. Halogens

  3. Hydrofluorocarbons

  4. All of the above

Show answer
Correct Option: D
Explanation:
The chemicals responsible for ozone layer destruction are:

  • Chlorofluorocarbons: Chlorofluorocarbons (CFCs) are non-toxic, non-flammable chemicals containing atoms of carbon, chlorine, and fluorine. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants.

  • Halogens: Ozone is destroyed by reactions with chlorine, bromine, nitrogen, hydrogen, and oxygen gases. Reactions with these gases typically occur through catalytic processes. Because of catalytic reactions, an individual chlorine atom, on an average, can destroy nearly a thousand ozone molecules, before it is converted into a form harmless to ozone.

  • Hydrofluorocarbons: The HFCs are a class of replacements for CFCs and affect the ozone layer.