Chemistry Class-11: Chapter – 14. Environmental Chemistry Part – 1 (For CBSE, ICSE, IAS, NET, NRA 2022)

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I. Multiple Choice Questions (Type-I)

Question: 1

Which of the following gases is not a greenhouse gas?





Answer: (i)

Question: 2

Photochemical smog occurs in warm, dry and sunny climate. One of the following is not amongst the components of photochemical smog, identify it.




(iv) Unsaturated hydrocarbon

Answer: (iii)

Question: 3

Which of the following statements is not true about classical smog?

(i) Its main components are produced by the action of sunlight on emissions of automobiles and factories.

(ii) Produced in cold and humid climate.

(iii) It contains compounds of reducing nature.

(iv) It contains smoke, fog and Sulphur dioxide.

Answer: (i)

Question: 4

Biochemical Oxygen Demand, is a measure of organic material present in water. value less than indicates a water sample to be ________.

(i) Rich in dissolved oxygen

(ii) poor in dissolved oxygen

(iii) highly polluted

(iv) not suitable for aquatic life

Answer: (i)

Question: 5

Which of the following statements is wrong?

(i) Ozone is not responsible for greenhouse effect.

(ii) Ozone can oxidize Sulphur dioxide present in the atmosphere to Sulphur trioxide.

(iii) Ozone hole is thinning of ozone layer present in stratosphere.

(iv) Ozone is produced in upper stratosphere by the action of UV rays on oxygen.

Answer: (i)

Question: 6

Sewage containing organic waste should not be disposed in water bodies because it causes major water pollution. Fishes in such a polluted water die because of

(i) Large number of mosquitoes

(ii) Increase in the amount of dissolved oxygen

(iii) Decrease in the amount of dissolved oxygen in water

(iv) Clogging of gills by mud.

Answer: (iii)

Question: 7

Which of the following statements about photochemical smog is wrong?

(i) It has high concentration of oxidizing agents.

(ii) It has low concentration of oxidizing agent.

(iii) It can be controlled by controlling the release of , hydrocarbons, ozone etc.

(iv) Plantation of some plants like Pinus helps in controlling photochemical smog.

Answer: (ii)

Question: 8

The gaseous envelope around the earth is known as atmosphere. The lowest layer of this is extended from sea level, this layer is ________.

(i) Stratosphere

(ii) Troposphere

(iii) Mesosphere

(iv) Hydrosphere

Answer: (ii)

Question: 9

Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form oxides of nitrogen because ________.

(i) the reaction is endothermic and requires very high temperature.

(ii) the reaction can be initiated only in presence of a catalyst.

(iii) oxides of nitrogen are unstable.

(iv) and are unreactive.

Answer: (iii)

Question: 10

The pollutants which come directly in the air from sources are called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?


(ii) Hydrocarbon

(iii) Peroxyacetyl nitrate


Answer: (iii)

Question: 11

Which of the following statements is correct?

(i) Ozone hole is a hole formed in stratosphere from which ozone oozes out.

(ii) Ozone hole is a hole formed in the troposphere from which ozone oozes out.

(iii) Ozone hole is thinning of ozone layer of stratosphere at some places.

(iv) Ozone hole means vanishing of ozone layer around the earth completely.

Answer: (iii)

Question: 12

Which of the following practices will not come under green chemistry?

(i) If possible, making use of soap made of vegetable oils instead of using synthetic detergents.

(ii) Using for bleaching purpose instead of using chlorine based bleaching agents.

(iii) Using bicycle for travelling small distances instead of using petrol/diesel based vehicles.

(iv) Using plastic cans for neatly storing substances.

Answer: (iv)

II. Multiple Choice Questions (Type-II)

In the following questions two or more options may be correct.

Question: 13

Which of the following conditions shows the polluted environment?

(i) pH of rain water is .

(ii) amount of carbon dioxide in the atmosphere is .

(iii) biochemical oxygen demand 10 ppm.

(iv) eutrophication.

Answer: (iii) . (iv)

Question: 14

Phosphate containing fertilisers cause water pollution. Addition of such compounds in water bodies causes ________.

(i) Enhanced growth of algae

(ii) Decrease in amount of dissolved oxygen in water

(iii) Deposition of calcium phosphate

(iv) Increase in fish population

Answer: (i) , (ii)

Question: 15

The acids present in acid rain are ________.

(i) Peroxyacetyl nitrate




Answer: (ii) , (iii) , (iv)

Question: 16

The consequences of global warming may be ________.

(i) increase in average temperature of the earth

(ii) melting of Himalayan Glaciers

(iii) increased biochemical oxygen demand

(iv) eutrophication

Answer: (i) , (ii)