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Environmental Chemistry Important Questions And Answers

Environmental Chemistry Important Questions And Answers

Environmental Chemistry is the most important and interesting chapter of Chemistry. So the practice set of Environmental Chemistry with Important Questions And Answers helps students of class 11 and also for students studying for various competitive exams. Students are advised to practice and understand all the questions accordingly.

1.The gas emitted by supersonic jet planes that slowly depletes the ozone layer is:

a) CO

b) NO

c) SO2

d) O2

2. The pH of normal rain-water is:

a) 6.5

b) 7.5

c) 5.6

d) 3.5

3.Which of the following is not a greenhouse gas?

a) Methane

b)  Ozone

c) Carbon dioxide

d) Nitrogen.

4.The process of ‘eutrophication’ is due to

a) increase in concentration of insecticide in water.

b) increase in concentration of fluoride ion in water.

c) the reduction in concentration of the dissolved oxygen in water due to phosphate pollution in water.

d) attack of younger leaves of a plant by peroxyacetyl nitrate.

5.The maximum prescribed concentration of cadmium in drinking water in ppm is:

a) 0.05

b)  3

c) 2

d) 0.005

6.Which of the following is true about photochemical smog?

a) It is reducing in nature

b) It is formed in winter

c) It is a mixture of smoke and fog

d) It causes irritation in eyes

7.The smog is essentially caused by the presence of:

a) O2 and O3

b) O2 and N2

c) Oxides of sulphur and nitrogen

d) O3 and N2 

8.London smog is found in:

a) Summer during day time

b) Summer during morning time

c) Winter during morning time

d) Summer during night time

9.Photochemical smog is formed in:

a) Summer during morning time

b)  Summer during day time

c) Winter during morning time

d) Winter during day time

10. Depletion of ozone layer causes:

a) blood cancer

b) lung cancer

c) Skin cancer

d) breast cancer

11.Pick up the correct statement:

a) CO which is a major pollutant resulting from the combustion of fuels in automobiles
plays a major role in photochemical smog.

b) Classical smog has an oxidizing character while the photochemical smog is reducing in

c)  Photochemical smog occurs in day time whereas the classical smog occurs in the
morning hours.

d) During formation of smog the level of ozone in the atmosphere goes down.

12.In Antarctica, ozone depletion is due to the formation of the following compound:

a) Acrolein

b) peroxy acetyl nitrate

c) SO2 and SO3

d) chlorine nitrate.

13.Excess nitrate in drinking water can cause:

a) methemoglobinemia

b)  kidney damage

c) liver damage

d) laxative effect.

14.What are the different layers of Atmosphere:

a) Hydrosphere

b) Lithosphere

c) Biosphere

d) all of  these.

15.Distinguish among Hydrosphere, Lithosphere, Biosphere.


   Hydrosphere   Lithosphere   Biosphere
It is the aqueous envelope of the earth. The solid rocky portion of the earth make up the lithosphere. The biological envelope which supports life is the biosphere
e.g., oceans. lakes etc. e.g., animal, human beings

16.Montreal protocol apply on:

a) 1987

b) 1985

c) 1956

d) 1999

17.Methemoglobinemia is :

a)  Excess of Sulphur

b) Excess of Nitrate 

c)  Excess of Phosphorus

d)  Excess of Chlorine

18.What is the meaning of 3r’s:

a) Reduce, Rechange and Refund

b) Reduce, Recycle and Refund

c) Reduce, Recycle and Reuse

d) Restore, Recycle and Reuse

19.Who is the father of Green Chemistry?

a) Schrödinger and John C.Warner

b) Paul Anasta and Maxwell

c) Maxwell and John C.Warner

d) Paul Anastas and John C.Warner

20.Bhopal Gas Tragedy helds on:

a) Dec 2, 1984

b) Dec 2, 1985

c) Dec 3, 1984

d) Nov 2, 1984

21.Which of the following is a greenhouse gas?

a) Methane

b) Nitrogen

c) Carbon dioxide

d) All of these

22.Identify the wrong statement in the following:

a) Ozone layer does not permit infrared radiation from the sun to reach the earth.

b) Acid rain is mostly because of oxides of nitrogen and sulphur.

c) Chlorofluorocarbons are responsible for ozone layer depletion

d) Green house effect is responsible for global warming.

23.Which of the following is the coldest region?

a) Troposphere

b) Mesosphere

c) Stratosphere

d) Thermosphere

24.Which of the following is a secondary pollutant?

a) CO2

b) NO2

c) PAN

d) SO2

25.All are primary pollutants except:

a)  SO2

b) NO2

c) H2SO4

d) Particulate matter

26.The gas leaked from a storage tank of the Union Carbide plant in Bhopal gas tragedy was:

a) Phosgene

b) Methylisocyanate

c) Methylamine

d) Ammonia

27.Which one of the following statement is not correct?

a) DDT and BHC are not good insecticides because they are highly soluble in water.

b) DDT and BHC are not good insecticides because they are absorbed by the soil and
contaminate food crops.

c) Aldrin is not a good insecticide because it is not biodegradable.

d) All the above are incorrect.

28.Green chemistry means such reactions which:

a) produce colour during reactions

b) reduce the use and production of hazardous chemicals

c)  are related to the depletion of ozone layer

d)  study the reactions in plants

29.Which one of the following statement is not true?

a) Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant

b) pH of drinking water should be between 5.5 – 9.5

c) Concentration of BOD below 6 ppm is good for the growth of fish

d)  Clean water would have a BOD value of less than 5 ppm

30.The aromatic compounds present as particulates are:

a) Benzene

b) Toluene

c) Nitrobenzene

d) Polycyclic hydrocarbons

31.Ozone layer is present in:

a) Troposphere

b) Stratosphere

c) Mesosphere

d) Exosphere

32.”Oxygen plays a key role in the troposphere while ozone in the stratosphere.


All biological activity takes place in the troposphere for which oxygen is required. Ozone in the stratosphere absorbs the harsh ultraviolet radiation coming from the sun which otherwise cause skin cancer, affect the cornea of the eye and may cause even blindness.

33.Fish do not grow as well in warm water as in cold water. Why?


The amount of dissolved oxygen in warm water is less than in cold water.

34.Why is acid rain considered as a threat to Taj Mahal?


Taj Mahal is made of marble. The acid rain contains H2SO4 which attacks the marble (CaCO3) there by   pitting it,discolouring it and making it lustreless.

CaCO3 + H2SO4 → CaSO4 + CO2 + H2O

35.Why does rain water normally have a pH of about 5.6? When does it become acid rain?


Normally rain has a pH of about 5.6 due to dissolution of CO2 of the atmosphere into it.When the pH of rain falls below 5.6, it becomes acid rain.

36. Differences between Biodegradable and Non-biodegradable substances:


    Biodegradable    Non-biodegradable
Biodegradable substances are those that degrades or break down naturally. Non-biodegradable substances are those that do not degrade easily.
Materials like plants, animals, their waste, paper, fruits, flowers, vegetables fall under biodegradable substances Rubber, plastic, chemicals, paint plastic falls under the category of the non-biodegradable items.

37.Soil conditioners containing toxic metals like:

a) Hg, Pb, As. Cd

b) Hg, P, As. Ca

c) H, Pb, At. Cd

d) Hg, Pb, As. Cr

38.HFC’S and PFC’s are used instead of which compound  that is somehow helping in saving the ozone  layer.

a) CFC’s

b) FMC’s

c) NO2

d) PAN

39.UNEP stands for:

a) United Nations Environment Program

b) United Nations Everst Program

c) United Nations Environment Presentation

d) none of these

40.The aromatic compounds not present as particulates are:

a) Nitrobenzene

b) Polycyclic hydrocarbons

c) both

d)  none of these

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