CBSE Class 11 Chemistry Environmental Chemistry MCQs Set B

Question: What is DDT among the following ?
a) Greenhouse gas
b) A fertilizer
c) Biodegradable pollutant
d) Non-biodegradable pollutant
Answer: d

Question: Which of the following statements is incorrect ?
a) Smoke particulates consist of solid or mixture of solid and liquid particles formed during combustion of organic matter.
b) Herbicides and insecticides that miss their target and travel through air form mists.
c) Organic solvents, metals and metallic oxides form fume particles
d) None of the options
Answer: d

 Question: Green chemistry means such reactions which
a) are related to the depletion of ozone layer
b) study the reactions in plants
c) produce colour during reactions
d) reduce the use and production of hazardous chemicals.
Answer: d

Question: About 20 km above the earth, there is an ozone layer. Which one of the following statements about ozone and ozone layer is true?
a) It is beneficial to us as it stops U.V. radiation.
b) Conversion of O₃ to O₂ is an endothermic reaction.
c) Ozone is a triatomic linear molecule.
d) It is harmful as it stops useful radiation.
Answer: a

Question: The region containing water vapour is
a) thermosphere
b) stratosphere
c) troposphere
d) mesosphere
Answer: c

Question: Today the concentration of green house gases is very high because of
a) use of refrigerator
b) increased combustion of oils and coal
c) deforestation
d) All of the options
Answer: d

Question: Which one of the following is responsible for depletion of the ozone layer in the upper strata of the atmosphere?
a) Polyhalogens
b) Ferrocene
c) Fullerenes
d) Freons 
Answer: d

Question: Which of the following strategy is not a correct approachto reduce global warming ?
a) Reducing the green house gas emission by limiting the use of fossil fuels
b) Increase the vegetation cover particularly the forest for photosynthetic utilization of CO₂
c) Minimizing the use of nitrogen fertilizers in agriculture for reducing N₂O emission
d) Increasing the use of air conditioners, refrigeration unit and production of plastic foams and propellants in aerosal spray cans
Answer: d

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

Question: The substance which is not regarded as a pollutant?
a) NO₂
b) CO₂
c) O₃
d) Hydrocarbons
Answer: b

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: a

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 is a sink for CO?
a) Microorganisms present in the soil
b) Oceans
c) Plants
d) Haemoglobin
Answer: a

Question: The substance having the largest concentration in acid rain
a) H₂CO₃
b) HNO₃
c) HCl
d) H₂SO₄
Answer: d

Question: Which one of the following statement is not true?
a) pH of drinking water should be between 5.5 – 9.5.
b) Concentration of DO below 6 ppm is good for the growth of fish.
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: b

Question: The greenhouse gas is
a) CO₂
b) SO₂
c) N₂
d) H₂S
Answer: a

Question: Which one of the following statements is not true?
a) Clean water would have a BOD value of 5 ppm.
b) Fluoride deficiency in drinking water is harmful. Soluble fluoride is often used to bring its concentration upto 1 ppm.
c) When the pH of rain water is higher than 6.5, it is called acid rain.
d) Dissolved Oxygen (DO) in cold water can reach a concentration upto 10 ppm.
Answer: c

Question: The gas emitted by supersonic jet planes that slowly depletes the concentration of ozone layer is
a) CO
b) NO
c) SO₂
d) O₂
Answer: b

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 main element of smog is
a) O₃ and PAN
b) O₃
c) PAN
d) PPN and PBN
Answer: a

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

Question: Which one of the following is not a common component of photochemical smog?
a) Ozone
b) Acrolein
c) Peroxyacetyl nitrate
d) Chlorofluorocarbons 
Answer: d

 Question: Photochemical smog is due to the presence of
a) oxides of sulphur
b) oxides of nitrogen
c) oxides of carbon
d) lead
Answer: b

Question: Which is related to ‘Green House Effect’?
a) Farming of Green plants
b) Farming of Vegetables in Houses
c) Global Warming
d) Biodegradable pollutant
Answer: c

Question: Which one of the following statements regarding photochemical smog is not correct?
a) Carbon monoxide does not play any role in photochemical smog formation.
b) Photochemical smog is an oxidising agent in character.
c) Photochemical smog is formed through photochemical reaction involving solar energy.
d) Photochemical smog does not cause irritation in eyes and throat. 
Answer: d

Question: Which of the following is the coldest region of atmosphere ?
a) Thermosphere
b) Mesosphere
c) Troposphere
d) Stratosphere
Answer: b

Question: High concentration of which of the following in atmosphere leads to stiffness of flower buds which eventually fall off from plants?
a) NO₂
b) SO₂
c) CFC
d) Smog
Answer: b

Question: The green house effect is caused by
a) CO₂
b) NO₂
c) NO
d) CO
Answer: a

Question: Classical smog occurs in places of
a) excess SO₂
b) low temperature
c) high temperature
d) excess NH₃
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: Air pollution causing photochemical oxidants production include
a) Carbon monoxide, sulphur dioxide
b) Nitrous oxide, nitric acid fumes, nitric oxide
c) Ozone, peroxyacetyl nitrate, aldehydes
d) Oxygen, chlorine, fuming nitric acid
Answer: c

Question: The uppermost region of the atmosphere is called
a) Ionosphere
b) Stratosphere
c) Troposphere
d) Exosphere
Answer: d 

Question: Which of the following is not correct about carbon monoxide?
a) It forms carboxyhaemoglobin.
b) It reduces oxygen carrying ability of blood.
c) The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.
d) It is produced due to incomplete combustion.
Answer: c

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 withoutthunderstorm 
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: a

Question: The non-viable particulate among the following is
a) Dust
b) Bacteria
c) Moulds
d) Fungi
Answer: a

Question: The region which is greatly affected by air pollution is
a) Thermosphere
b) Stratosphere
c) Troposphere
d) Mesosphere
Answer: c

Question: The secondary precursors of photochemical smog are
a) SO₂ and NO₂
b) SO₂ and hydrocarbons
c) NO₂ and hydrocarbons
d) O₃ and PAN
Answer: d

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

Question: The greenhouse effect is because of the
a) presence of gases, which in general are strong infraredabsorbers, 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: a

Question: The quantity of CO₂ in atmosphere is
a) 3.34%
d) 6.5%
c) 0.034%
d) 0.34%
Answer: c

Question: The pH of normal rain water is
a) 6.5
b) 7.5
c) 5.6
d) 3.5
Answer: c

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) O₃ and N₂
Answer: a

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) hydrocarbons, ozone and SO_x
Answer: a

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 earthwhile far from earth these have wavelength independent behaviour.
Answer: a

Question: Carbon monoxide (CO) is harmful to man because
a) it forms carbolic acid
b) it generates excess CO₂
c) it is carcinogenic
d) it competes with O₂ for haemoglobin
Answer: d

Question: Acid rain is due to
a) CH₃
b) N₂O₅
c) SO₂ and NO₂
d) C₂H₅OH
Answer: c

Question: The pollutants which came directly in the air from sourcesare called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants. Which of the ollowing belongs to secondary air pollutants?
a) C O
b) Hydrocarbon
c) Peroxyacetyl nitrate
Answer: c

 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 (iii)
b) (i) and (ii)
c) (ii) and (iv)
d) (i) and (iii)
Answer: c

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) (ii) only b) (i) and (ii)
c) (iii) and (iv)
d) (i), (ii), (iii) and (iv)
Answer: d

 Question: The irritant red haze in the traffic and congested placesis 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) (i), (iv) and (v)
b) (iii) only
c) (ii) only
d) (ii) and (v)
Answer: c