JEE Chemistry Environmental Chemistry MCQs Set A

Question:  The type of pollution caused by spraying of DDT is

• a) air, water and soil
• b) air and water
• c) air and soil
• d) air

Answer: air, water and soil

Question: What is DDT among the following ?

• a) Non-biodegradable pollutant
• b) Biodegradable pollutant
• c) A fertilizer
• d) Greenhouse gas

Answer: Non-biodegradable pollutant

Question: The uppermost region of the atmosphere is called

• a) Exosphere
• b) Stratosphere
• c) Ionosphere
• d) Troposphere

Answer: Exosphere

Question: Which of the following is the coldest region of atmosphere ?

• a) Mesosphere
• b) Stratosphere
• c) Thermosphere
• d) Troposphere

Answer: Mesosphere

Question: The region which is greatly affected by air pollution is

• a) Troposphere
• b) Thermosphere
• c) Stratosphere
• d) Mesosphere

Answer: Troposphere

Question: The region containing water vapour is

• a) troposphere
• b) thermosphere
• c) stratosphere
• d) mesosphere

Answer: troposphere

Question: High concentration of which of the following in atmosphere leads to stiffness of flower buds which eventually fall off from plants?

• a) SO₂
• b) Smog
• c) NO₂
• d) CFC

Answer: SO₂

Question: The irritant red haze in the traffic and congested places is due to presence of which of the following ?

(i) Oxides of sulphur
(ii) Oxides of nitrogen
(iii) Carbon dioxide
(iv) Mists, smoke and dust
(v) Smog

• a)  (ii) only
• b) (i), (iv) and (v)
• c) (iii) only
• d) (ii) and (v)

Answer: (ii) only

Question: The quantity of CO₂ in atmosphere is

• a) 0.034%
• b) 3.34%
• c) 6.5%
• d) 0.34%

Answer: 0.034%

Question: The substance which is not regarded as a pollutant?

• a) CO₂
• b) Hydrocarbons
• c) NO₂
• d) O₃

Answer: CO₂

Question: Which of the following is/are the hazardous pollutant(s) present in automobile exhaust gases?

(i) N₂     (ii) CO
(iii) CH₄ (iv) Oxides of nitrogen

• a) (ii) and (iv)
• b) (ii) and (iii)
• c) (i) and (ii)
• d) (i) and (iii)

Answer: (ii) and (iv)

Question: The gas emitted by supersonic jet planes that slowly depletes the concentration of ozone layer is

• a) NO
• b) CO
• c) SO₂
• d) O₂

Answer: NO

Question: Carbon monoxide (CO) is harmful to man because

• a) it competes with O₂ for haemoglobin
• b) it is carcinogenic
• c) it generates excess CO₂
• d) it forms carbolic acid

Answer: it competes with O₂ for haemoglobin

Question: Increase in global temperature increases the incidence of which of the following infectious disease(s)

(i) Sleeping sickness (ii) Yellow fever
(iii) Malaria (iv) Dengue

• a) (i), (ii), (iii) and (iv)
• b) (i) and (ii)
• c) (ii) only
• d) (iii) and (iv)

Answer: (i), (ii), (iii) and (iv)

Question: The green house effect is caused by

• a) CO₂
• b) NO
• c) NO₂
• d) CO

Answer: CO₂

Question: Which is related to ‘Green House Effect’?

• a) Global Warming
• b) Biodegradable pollutant
• c) Farming of Vegetables in Houses
• d) Farming of Green plants

Answer: Global Warming

Question: Green house gases

• a) allow shorter wavelength to enter earth's atmosphere while doesn't allow longer wavelength to leave the earth's atmosphere
• b) allow longer wavelength to enter earth atmosphere while doesn't allow shorter wavelength to leave the surface
• c) don't have wavelength specific character
• d) show wavelength specific behaviour near the earth while far from earth these have wavelength independent behaviour.

Answer:  allow shorter wavelength to enter earth's atmosphere while doesn't allow longer wavelength to leave the earth's atmosphere

Question: Today the concentration of green house gases is very high because of

• a) All of the above
• b) deforestation
• c) increased combustion of oils and coal
• d) use of refrigerator

Answer: All of the above

Question: The greenhouse effect is because of the

• a) presence of gases, which in general are strong infrared absorbers, in the atmosphere
• b) presence of CO₂ only in the atmosphere
• c) pressure of O₃ and CH₄ in the atmosphere
• d) N₂O and chlorofluorohydrocarbons in the atmosphere

Answer: presence of gases, which in general are strong infrared absorbers, in the atmosphere

Question: The greenhouse gas is

• a) CO₂
• b) N₂
• c) SO₂
• d) H₂S

Answer: CO₂

Question: Which of the following gases is not a green house gas?

• a) CO
• b) O₃
• c) CH₄
• d) H₂O vapour

Answer: CO

Question: Which of the following strategy is not a correct approach to reduce global warming ?

• a) Increasing the use of air conditioners, refrigeration unit and production of plastic foams and propellants in aerosal spray cans
• b) Minimizing the use of nitrogen fertilizers in agriculture for reducing N₂O emission
• c) Increase the vegetation cover particularly the forest for photosynthetic utilization of CO₂
• d) Reducing the green house gas emission by limiting the use of fossil fuels

Answer: Increasing the use of air conditioners, refrigeration unit and production of plastic foams and propellants in aerosal spray cans

Question: The substance having the largest concentration in acid rain

• a) H₂SO₄
• b) HNO₃
• c) H₂CO₃
• d) None of these

Answer: H₂SO₄

Question: When rain is accompanied by a thunderstorm, the collected rain water will have a pH value

• a) slightly lower than that of rain water without thunderstorm
• b) slightly higher than that when the thunderstorm is not there
• c) uninfluenced by occurrence of thunderstorm
• d) which depends upon the amount of dust in air

Answer: slightly lower than that of rain water without thunderstorm

Question: Acid rain is due to

• a) SO₂ and NO₂
• b) CH₃
• c) N₂O₅
• d) None of these

Answer: SO₂ and NO₂

Question: The pH of normal rain water is

• a) 5.6
• b) 6.5
• c) 7.5
• d) 3.5

Answer: 5.6

Question: Which of the following statements is incorrect ?

• a) None of these
• b) Organic solvents, metals and metallic oxides form fume particles
• c) Herbicides and insecticides that miss their target and travel through air form mists
• d) Smoke particulates consist of solid or mixture of solid and liquid particles formed during combustion of organic matter

Answer: None of these

Question: Which of the following green house gas is released in paddy field ?

I. CFCs II. CH₄ III. SO₂

• a) Only II
• b) I and II
• c) Only I
• d) Only III

Answer: Only II

Question: Photochemical smog is due to the presence of

• a) oxides of nitrogen
• b) lead
• c) oxides of sulphur
• d) oxides of carbon

Answer: oxides of nitrogen

Question: The secondary precursors of photochemical smog are

• a) O₃ and PAN
• b) NO₂ and hydrocarbons
• c) SO₂ and hydrocarbons
• d) SO₂ and NO₂

Answer: O₃ and PAN

Question: The main element of smog is

• a) O₃ and PAN
• b) PAN
• c)  O₃
• d) PPN and PBN

Answer: O₃ and PAN

Question: Classical smog occurs in places of

• a) low temperature
• b) excess NH₃
• c) excess SO₂
• d) high temperature

Answer: low temperature

Question: The smog is essentially caused by the presence of

• a) Oxides of sulphur and nitrogen
• b) O₂ and N₂
• c) O₂ and O₃
• d) None of these

Answer:  Oxides of sulphur and nitrogen

Question: Air pollution causing photochemical oxidants production include

• a) Ozone, peroxyacetyl nitrate, aldehydes
• b) Oxygen, chlorine, fuming nitric acid
• c) Nitrous oxide, nitric acid fumes, nitric oxide
• d) Carbon monoxide, sulphur dioxide

Answer: Ozone, peroxyacetyl nitrate, aldehydes

Question: Photochemical smog formed in congested metropolitan cities mainly consists of

• a) ozone, peroxyacetyl nitrate and NO_x
• b) smoke, peroxyacetyl nitrate and SO₂
• c) hydrocarbons, SO₂ and CO₂
• d) None of these

Answer: ozone, peroxyacetyl nitrate and NO_x

Question: In almost all Indian metropolitan cities like Delhi, the major atmospheric pollutant(s) is/are

• a) suspended particulate matter (SPM)
• b) oxides of sulphur
• c) carbon dioxide and carbon monoxide
• d) oxides of nitrogen

Answer: suspended particulate matter (SPM)

Question:  The non-viable particulate among the following is

• a) Dust
• b) Moulds
• c) Bacteria
• d) Fungi

Answer: Dust

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) SO₂
• b) Unsaturated hydrocarbon
• c) O₃
• d) NO₂

Answer: SO₂

Question: The pollutants which came 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) Peroxyacetyl nitrate
• b) C O
• c) Hydrocarbon
• d) NO

Answer:  Peroxyacetyl nitrate

Question: The main element of smog is

• a) O₃ and PAN
• b) PAN
• c) O₃
• d) None of these

Answer: O₃ and PAN

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

Question: Which of the following statements about photochemical smog is wrong?

• a) It has low concentration of oxidising agent
• b) It has high concentration of oxidising agents
• 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: It has low concentration of oxidising agent

Question: Select the process that does not add particulate materials to air

• a) Use of air conditioner
• b) Burning of fosssil fuels
• c) Paper industry
• d) Incomplete combustion of coal

Answer: Use of air conditioner

Question: The biggest particulate matter is

• a) Fly ash
• b) Soot
• c) HNO₃ droplets
• d) None of these

Answer: Fly ash

Question: The viable particulate among the following is

• a) Algae
• b) Mist
• c) Fumes
• d) Smoke

Answer: Algae

Question: The aromatic compounds present as particulates are

• a) Polycyclic aromatic hydrocarbons
• b) Benzene
• c) Toluene
• d) Nitrobenzene

Answer: Polycyclic aromatic hydrocarbons

Question: Which of the following can control the photochemical smog ?

(A) Use of catalytic converters in automobiles.
(B) Plantation of trees like pinus, pyrus vitis etc.
(C) Using less sulphur containing fossil fuels.

• a) A and B
• b) A and C
• c) B
• d) A, B and C

Answer: A and B

Question: The gas responsible for ozone depletion

• a) NO and freons
• b) CO₂
• c) SO₂
• d) CO

Answer: NO and freons

Question: Identify the incorrect statement from the following

• a) Ozone absorbs infrared radiation
• b) Oxides of nitrogen in the atmosphere can cause the depletion of ozone layer
• c) Ozone absorbs the intense ultraviolet radiation of the sun.
• d) None of these

Answer: Ozone absorbs infrared radiation

Question: 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) Greenhouse effect is responsible for global warming
• d) Chlorofluorocarbons are responsible for ozone layer depletion.

Answer: Ozone layer does not permit infrared radiation from the sun to reach the earth

Question: Which of the following chemical, harmful to ozone, is released by chlorofluoro carbon?

• a) Chlorine
• b) Sulphur dioxide
• c) Fluorine
• d) Nitrogen dioxide

Answer: Chlorine

Question: In Antarctica ozone depletion is due to the formation of following compound

• a) acrolein
• b) peroxyacetyl nitrate
• c) chlorine nitrate
• d) SO₂ and SO₃

Answer: acrolein

Question: Depletion of ozone layer causes

• a) skin cancer
• b) blood cancer
• c) breast cancer
• d) lung cancer

Answer: skin cancer

Question: Select the one that has an adverse effect on ozone layer

• a) Chlorofluorocarbons
• b) Dust particles
• c) Carbon dioxide
• d) Soil

Answer: Chlorofluorocarbons

Question: Ozone hole refers to

• a) Reduction in thickness of ozone layer in stratsophere
• b) Reduction in thickness of ozone layer in troposphere
• c) Hole in ozone layer
• d) Increase in concentration of ozone

Answer: Reduction in thickness of ozone layer in stratsophere

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: Ozone is not responsible for green house effect

Question: Which of the following statements is correct?

• a) Ozone hole is thinning of ozone layer of stratosphere at some places
• b) Ozone hole is a hole formed in the troposphere from which ozone oozes out.
• c) Ozone hole is a hole formed in stratosphere from which ozone oozes out
• d) None of these

Answer: Ozone hole is thinning of ozone layer of stratosphere at some places

Question: Ozone is an important constituent of stratosphere because it

• a) Absorbs ultraviolet radiation which is harmful to human life
• b) Removes poisonous gases of the atmosphere by reacting with them
• c) Prevents the formation of smog over large cities
• d) Destroys bacteria which are harmful to human life

Answer: Absorbs ultraviolet radiation which is harmful to human life

Question: The gas(es) not responsible for ozone depletion

• a) SO₂
• b) NO and freons
• c) CO₂
• d) None of these

Answer: SO₂

Question: What is the concentration of dissolved oxygen in cold water ?

• a) 10 ppm
• b) 100 ppm
• c) 5 ppm
• d) 200, 000 ppm

Answer: 10 ppm

Question: Water pollution is caused by

• a) pesticides
• b) SO₂
• c) CO₂
• d) O₂

Answer: pesticides

Question: Minamata disease of Japan is due to pollution of

• a) Mercury
• b) Lead
• c) Aresenic
• d) Cynide

Answer: Mercury

Question: The high amount of E. coli in water is the indicator of

• a) sewage pollution
• b) industrial pollution
• c) hardness of water
• d) presence of chlorine in water

Answer: sewage pollution

Question: A lake with an inflow of domestic sewage rich in organic waste may result in

• a) death of fish due to lack of oxygen
• b) increased population of aquatic food web organisms
• c) an increase production of fish due to lot of nutrients
• d) drying of the lake very soon due to algal bloom

Answer: death of fish due to lack of oxygen

Question: Which of the following does not occur when the sewage is discharged into water ?

• a) Increase in O₂
• b) Cyanophycean blooms occur
• c) Eutrophication
• d) None of these

Answer: Increase in O₂

Question: Which of the following metal is a water pollutant and causes sterility in human being

• a) Mn
• b) Hg
• c) As
• d) Mg

Answer: Mn

Question: Sewage mostly constitutes

• a) Biodegradable pollutants
• b) Non-biodegradable pollutants
• c) Effluents
• d) None of  these

Answer: Biodegradable pollutants

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) decrease in the amount of dissolved oxygen in water
• b) clogging of gills by mud
• c) increase in the amount of dissolved oxygen
• d) None of these

Answer: decrease in the amount of dissolved oxygen in water

Question: Sewage water is purified by

• a) microoganisms
• b) fishes
• c) aquatic plants
• d) light

Answer: microoganisms

Question: Water is often treated with chlorine to

• a) kill germs
• b) increase oxygen content
• c) remove hardness
• d) remove suspended particles

Answer: kill germs

Question: Which causes death of fish in water bodies polluted by sewage?

• a) Decrease in D.O.
• b) Pathogens
• c) Foul smell
• d) Herbicides

Answer: Decrease in D.O.

Question: B.O.D. test or biochemical oxygen demand test is made for measuring

• a) water pollution
• b) soil pollution
• c) air pollution
• d) noise pollution

Answer: water pollution

Question: Brewery and sugar factory waste alters the quality of a water body by increasing

• a) COD and BOD
• b) turbidity
• c) temperature
• d) pH

Answer: COD and BOD

Question: Brewery and sugar factory waste alters the quality of a water body by increasing

• a) COD and BOD
• b) turbidity
• c) temperature
• d) pH

Answer: COD and BOD

Question: Which one of the following statement is not true ?

• a) Concentration of DO below 6 ppm is good for the growth of fish.
• b) pH of drinking water should be between 5.5 – 9.5
• c) Clean water would have a BOD value of less than 5 ppm.
• d) Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant

Answer: Concentration of DO below 6 ppm is good for the growth of fish.

Question: Limit of BOD prescribed by Central pollution Control Board for the discharge of industrial and municipal waste waters into natural surface waters, is

• a) < 30 ppm
• b) < 10 ppm
• c) < 100 ppm
• d) < 3.0 ppm

Answer: < 30 ppm

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: rich in dissolved oxygen

Question: Phosphate fertilizers when added to water leads to

• a) Nutrient enrichment (eutrophication)
• b) Increased algal growth
• c) Reduced algal growth
• d) Increased growth of decomposers

Answer: Nutrient enrichment (eutrophication)

Question: BOD of pond is connected with

• a) Microbes & organic matter
• b) Organic matter
• c) Microbes
• d) None of these

Answer: Microbes & organic matter

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

• a) 0.005
• b) 3
• c) 0.05
• d) 2

Answer: 0.005

Question: Excess nitrate in drinking water can cause

• a) methemoglobinemia
• b) liver damage
• c) kidney damage
• d) laxative effect

Answer: methemoglobinemia

Question: Eutrophication causes reduction in

• a) dissolved oxygen
• b) nutrients
• c) dissolved salts
• d) All of the above

Answer: dissolved oxygen