CBSE Class 11 Chemistry Environmental Chemistry MCQs

Question : Which of the following statements about photochemical smog is wrong?
a) It has high concentration of oxidizing agents
b) It has low concentration of oxidizing agents
c) It can be controlled by controlling the release of NO₂, hydrocarbon, ozone, etc.
d) Plantation of some plants like pinus helps in controlling photochemical smog.

Answer :  B

Question : B.O.D is connected with
a) Organic matter
b) Microbes
c) Both
d) None

Answer :  C

Green chemistry means such reasons 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

Answer :  B

Question : Which is the greatest air pollutant these days
a) Factories
b) Motor vehicles
c) Domestic appliances
d) animals

Answer : D

Question : Which oxide of nitrogen is not a common pollutant introduced into the atmosphere both due to natural and human activity?
a) N₂O₅
b) NO₂
c) N₂O
d) NO

Answer : A

Question : Which of the following statements is correct?
a) Ozone hole is a hole formed in stratosphere from which ozone oozes out
b) Ozone hole is a hole formed in troposphere from which ozone oozes out
c) Ozone hole is thinning of ozone layer of stratosphere at some places
d) Ozone hole means vanishing of ozone layer around the earth completely

Answer :  C

Question : Among the following, the one that is not a green house gas is:
a) sulphur dioxide
b) nitrous oxide
c) methane
d) ozone

Answer : A

Question : The concentration of Peroxy Acetyl Nitrate (PAN) maximum in:-
a) Fog
b) Smoke
c) Smog
d) Photochemical smog

Answer :  D

Question : Which of the following statements is correct?
a) Ozone hole is a hole formed in stratosphere from which ozone oozes out.
b) Ozone hole is a hole formed in the troposphere from which ozone oozes out.
c) Ozone hole is thinning of ozone layer of stratosphere at some places.
d) Ozone hole means vanishing of ozone layer around the earth completely.

Answer :  C

Question : Which of the following practices will not come under green chemistry?
a) If possible, making use of soap made of vegetable oils instead of using synthetic detergents.
b) Using H₂O₂ for bleaching purpose instead of using chlorine based bleaching agents.
c) Using bicycle for travelling small distances instead of using petrol/diesel based vehicles.
d) Using plastic cans for neatly storing substances.

Answer :  D

Question : Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form oxides of nitrogen because _______.
a) the reaction is endothermic and requires very high temperature.
b) the reaction can be initiated only in presence of a catalyst.
c) oxides of nitrogen are unstable.
d) N₂ and O₂ are unreactive.

Answer :  A

Question : The living organisms on or around the earth constitute
a) Biome
b) Biosphere
c) Community
d) Biocoenosis

Answer :  B

Question : Which country has the greatest contribution for the hole formation in ozone layer?
a) Russia
b) Japan
c) USA
d) Germany

Answer :  C

Question : The population of India is 15% of the world but its annual energy consumption is only
a) 0.2%
b) 0%
c) 10%
d) 25%

Answer :  B

Question : The major source of BOD in the river Ganga is
a) Leaf litter
b) Fishes
c) Human waste
d) Aquatic plants

Answer :  C

Question : Which will not cause any atmospheric pollution
a) Hydrogen
b) Sulphur dioxide
c) Carbon dioxide
d) Carbon monoxide

Answer : A

Question : Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form dioxides of nitrogen because ______.
a) the reaction is endothermic and requires very high temperature
b) the reaction can be initiated only in presence of a catalyst
c) oxides of nitrogen are unstable
d) N₂ and O₂ are unreactive

Answer : A

The substance having the largest concentration in acid rain?
a) H₂CO₃
b) HNO₃
c) HCL
d) H₂SO₄

Answer :  D

Question : Photochemical smog occurs in warm, dry and sunny climate. One of the following is not amongst the components of photochemical smog, identify it.
a) NO₂
b) O₃
c) SO₂
d) Unsaturated hydrocarbon

Answer :  C

Question : Pollution can be controlled by
a) Sewage treatment
b) Checking atomic blasts
c) Manufacturing electrically operated vehicles
d) All the above

Answer :  D

Question : What is the intensity of sound in normal conversation
a) 10 -20 decibal
b) 30 - 60 decibal
c) 70 - 90 decibal
d) 120 - 150 decibal

Answer :  B

Question :  Which of the following statements about photochemical smog is wrong?
a) It has high concentration of oxidising agents.
b) It has low concentration of oxidising agent.
c) It can be controlled by controlling the release of NO₂ , hydrocarbons,ozone etc.
d) Plantation of some plants like pinus helps in controlling photochemical smog.

Answer :  B

Question :  Which of the following statements is correct?
a) Ozone hole is a hole formed in stratosphere from which ozone oozes out.
b) Ozone hole is a hole formed in the troposphere from which ozone oozes out.
c) Ozone hole is thinning of ozone layer of stratosphere at some places.
d) Ozone hole means vanishing of ozone layer around the earth completely.

Answer :  C

Question : Which of the following statement is NOT true about acid rain ?
a) It is due to reaction of SO₂, NO₂ and CO₂ with rain water
b) Causes no damage to monuments like Taj Mahal.
c) It is harmful to plants.
d) Its pH is less than 5.6

Answer :  B

Question : The type of pollution caused by spraying of DDT
a) Air and soil
b) Air and water
c) Air
d) Air, water and soil

Answer :  D

Question : Biochemical Oxygen Demand, (BOd) is a measure of organic material present in water. BOD value less than 5 ppm indicates a water sample to be __________.
a) rich in dissolved oxygen.
b) poor in dissolved oxygen.
c) highly polluted.
d) not suitable for aquatic life.

Answer :  A 

Question : 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?
a) CO
b) Hydrocarbon
c) Peroxyacetyl nitrate
d) NO

Answer :  C

Question : Dinitrogen and dioxygen are main constituents of air but these do not react with each other to form oxides of nitrogen because _________.
a) the reaction is endothermic and requires very high temperature.
b) the reaction can be initiated only in presence of a catalyst.
c) oxides of nitrogen are unstable.
d) N₂ and O₂ are unreactive.

Answer :  A

Question : The compound essential for the process of photosynthesis has this element
a) Ca
b) Ba
c) Fe
d) Mg

Answer :  D

Question : Which of the following practices will not come under green chemistry?
a) If possible, making use of soap made of vegetable oils instead of using synthetic detergents.
b) Using H₂O₂ for bleaching purpose instead of using chlorine based bleaching agents.
c) Using bicycle for travelling small distances instead of using petrol/ diesel based vehicles.
d) Using plastic cans for neatly storing substances.

Answer :  B

Question : Find the incorrect statement
a) BOD value of clean water is less than 5 ppm
b) Drinking water pH should be between 5.5-9.5
c) carbon, sulphur and nitrogen oxides are the most widespread air pollutants
d) dissolved oxygen concentration below 5 ppm is ideal for the growth of fish

Answer :  D

Question : Phosphate containing fertilisers cause water pollution. Addition of such compounds in water bodies causes __________.
a) enhanced growth of algae.
b) decrease in amount of dissolved oxygen in water.
c) deposition of calcium phosphate.
d) increase in fish population.

Answer :  A

Question : In the air, N₂ and O₂ occur naturally but they do not react to form oxides of nitrogen because
a) oxides of nitrogen are unstable
b) catalyst is required for the reaction
c) the reaction is endothermic
d) N₂ and O₂ do not react with each other

Answer :  C

Question : Which of the following gases is not a green house gas?
a) CO
b) O₃
c) CH₄
d) H₂O vapour

Answer :  A

Question : Photochemical smog occurs in warm, dry and sunny climate. One of the following is not amongst the components of photochemical smog, identify it.
a) NO₂
b) O₃
c) SO₂
d) Unsaturated hydrocarbon

Answer :  C

Question : The gaseous envelope around the earth is known as atmosphere. The lowest layer of this is extended upto 10 km from sea level, this layer is _________.
a) Stratosphere
b) Troposphere
c) Mesosphere
d) Hydrosphere

Answer :  B

Question : Which of the following statements is not true about classical smog?
a) Its main components are produced by the action of sunlight on emissions of automobiles and factories.
b) Produced in cold and humid climate.
c) It contains compounds of reducing nature.
d) It contains smoke, fog and sulphur dioxide.

Answer :  A

Question : Biochemical Oxygen Demand, (BOd) is a measure of organic material present in water. BOD value less than 5 ppm indicates a water sample to be __________.
a) rich in dissolved oxygen.
b) poor in dissolved oxygen.
c) highly polluted.
d) not suitable for aquatic life.

Answer :  A

Question : Which of the following statements is wrong?
a) Ozone is not responsible for green house effect.
b) Ozone can oxidise sulphur dioxide present in the atmosphere to sulphur trioxide.
c) Ozone hole is thinning of ozone layer present in stratosphere.
d) Ozone is produced in upper stratosphere by the action of UV rays on oxygen.

Answer :  A

Question : 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
a) Large number of mosquitoes.
b) Increase in the amount of dissolved oxygen.
c) Decrease in the amount of dissolved oxygen in water.
d) Clogging of gills by mud.

Answer :  C