Environmental Chemistry Practice Questions - DPP for JEE

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1. (b) High concentration of SO
2
 leads to stiffness of flower buds.
2. (a) Radiation coming from sun or outerspace have high energy or
short wavelength, which are allowed to enter by green house gases.
However, radiation emitted by earth is in infrared region, having
long wavelength, are reflected back by the envelope of green
house gases.
3. (b) Pesticides and synthetic fertilizers pollute the soil.
4. (c) Water is often treated with Cl
2
 to kill germs.
5. (c) CO and oxides of Nitrogen are poisonous gases present in
automobile exhaust gases.
6. (b) This represents a great step forward for green chemistry.
7. (a) Normal rain water has pH 5.6. Thunderstorm results in the
formation of NO and HNO
3
 which lowers the pH.
8. (c) The irritant red haze in the traffic and congested places is due to
presence of oxides of nitrogen.
9. (c) Photochemical smog is formed in noon in summer.
10. (b) Strength of sewage or degree of water pollution is measured in
terms of BOD (Biochemical oxygen demand) value.
11. (a) Photochemical smog is caused by oxides of sulphur and nitrogen.
12. (d) Aerosols use CFC and flying jets release NO. Both causes
depletion of ozone layer.
13. (c) The ozone layer, existing between 20 to35 km above the earth’s
surface, shield the earth from the harmful U. V. radiations from the
sun.
Depletion of ozone is caused by oxides of nitrogen
 + hv  NO + N
  reactive nitric oxide
NO +    + 
 + hv   + O
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1. (b) High concentration of SO
2
 leads to stiffness of flower buds.
2. (a) Radiation coming from sun or outerspace have high energy or
short wavelength, which are allowed to enter by green house gases.
However, radiation emitted by earth is in infrared region, having
long wavelength, are reflected back by the envelope of green
house gases.
3. (b) Pesticides and synthetic fertilizers pollute the soil.
4. (c) Water is often treated with Cl
2
 to kill germs.
5. (c) CO and oxides of Nitrogen are poisonous gases present in
automobile exhaust gases.
6. (b) This represents a great step forward for green chemistry.
7. (a) Normal rain water has pH 5.6. Thunderstorm results in the
formation of NO and HNO
3
 which lowers the pH.
8. (c) The irritant red haze in the traffic and congested places is due to
presence of oxides of nitrogen.
9. (c) Photochemical smog is formed in noon in summer.
10. (b) Strength of sewage or degree of water pollution is measured in
terms of BOD (Biochemical oxygen demand) value.
11. (a) Photochemical smog is caused by oxides of sulphur and nitrogen.
12. (d) Aerosols use CFC and flying jets release NO. Both causes
depletion of ozone layer.
13. (c) The ozone layer, existing between 20 to35 km above the earth’s
surface, shield the earth from the harmful U. V. radiations from the
sun.
Depletion of ozone is caused by oxides of nitrogen
 + hv  NO + N
  reactive nitric oxide
NO +    + 
 + hv   + O
 + O  NO + 
2 + hv  3 (Net reaction)
The presence of oxides of nitrogen increase the decomposition of .
14. (a) PSCs react with chlorine nitrate and HCl to give HOCl and Cl
2
.
15. (d) Using plastic cans for neatly storing substances will not come
under green chemistry. The plastic materials are non-
biodegradable.
16. (d) Addition of phosphate fertilizers to water leads to nutrient
enrichment (eutrophication)
17. (a) Based on the features given gas must be SO
2
 .
18. (b) Sewage water is purified by micro-organisms.
19. (d) CO is highly toxic and impairs respiration. CO combine with
haemoglobin of blood and reduces its O
2
 carry capacity.
20. (d) Acid rain is the rain water containing sulphuric acid and nitric acid
which are formed from the oxides of sulphur and nitrogen present
in the air as pollutants and rain water has a pH range of 4-5.
21. (d) The oxidised hydrocarbons and ozone in presence of humidity
cause photochemical smog.
Hydrocarbons + O
2
, NO
2
, NO, O, O
3
 ? Peroxides, formaldehyde,
peroxyacetyl-nitrate (PAN), acrolein etc. Hence
chlorofluorocarbons are not common component of photochemical
smog.
22. (a) Microorganisms present in the soil is a sink for CO.
23. (b) The ideal value of D.O for growth of fishes is 8 mg/ . 7mg / l is
desirable range, below this value fishes get susceptible to disease.
A value of 2 mg/ or below is lethal for fishes.
24. (c) The excess of fluorine in water causes fluorosis. The symptoms of
fluorosis are mottling of teeth (yellowish streaks) and abnormal
bones liable to fracture etc. It is an example of endemic disease.
25. (d) Minamata is caused by Hg poisoning.