Learn Environmental Chemistry MCQ questions & answers in Inorganic Chemistry are available for students perparing for IIT-JEE, NEET, Engineering and Medical Enternace exam.
81.
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 :
Ozone hole is thinning of ozone layer of stratosphere at some places.
No explanation is given for this question. Let's discuss the answer together.
82.
Which of the following chemical, harmful to ozone, is released by chlorofluorocarbon ?
83.
Synthesis of ethanal commercially from which of the following reagent is the part of green chemistry ?
A
$$C{H_3}C{H_2}OH$$
B
$$C{H_2} = C{H_2}$$
C
$$HC \equiv CH$$
D
$${\text{All of these}}$$
Answer :
$$C{H_2} = C{H_2}$$
Ethanal is commerically prepared by one step oxidation of ethene in the presence of ionic catalyst in aqueous medium with an yield of $${\text{90% }}{\text{.}}$$
\[\text{C}{{\text{H}}_{2}}=C{{H}_{2}}+{{O}_{2}}\xrightarrow[\begin{smallmatrix}
Pb(II)|Cu(II) \\
\text{(in water)}
\end{smallmatrix}]{\text{Catalyst}}C{{H}_{3}}CHO\]
84.
Increased level of greenhouse gases causes global warming which will result in
A
biomagnification
B
eutrophication
C
melting of glaciers
D
ozone depletion
Answer :
melting of glaciers
Global warming may result in increase in average temperature of the earth and melting of glaciers.
85.
As $$DDT$$ passes into food chain, its concentration
A
remains same
B
decreases
C
becomes zero
D
increases
Answer :
increases
With every trophic level in the food chain the concentration of $$DDT$$ increases.
86.
Which one of the following substances used in dry cleaning is a better strategy to control environmental pollution ?
A
Sulphur dioxide
B
Carbon dioxide
C
Nitrogen dioxide
D
Tetrachloroethylene
Answer :
Tetrachloroethylene
Tetrachloroethylene is widely used for drycleaning fabrics and metal degreasing
operations.
87.
Which among the following statements is $$false?$$
A
Oil slick in sea water increases $$D.O.$$ value
B
The main reason for river water pollution is industrial and domestic sewage discharge
C
Surface water contains a lot of organic matter mineral nutrients and radioactive materials
D
Oil spill in sea water causes heavy damage to fishery
Answer :
Oil slick in sea water increases $$D.O.$$ value
Oil slick in sea water decreases $$D.O.$$ value.
88.
Which of the following practices involve green chemistry?
(i) Substitute $$CFCs$$ by environmental friendly $$HFCs$$ and other compounds.
(ii) Replace halogenated solvent by liquid $$C{O_2}$$ for drycleaning.
(iii) Use of $${H_2}{O_2}$$ for bleaching instead of $$C{l_2}.$$
A
(i) and (ii) only
B
(ii) and (iii) only
C
(i) and (iii) only
D
(i), (ii) and (iii)
Answer :
(i), (ii) and (iii)
$$HFCs$$ are considered to be more friendly to environment. Use of tetrachloroethene as a solvent in dry cleaning industry has been replaced by liquefied $$C{O_2}$$ along with a suitable detergent which is less harmful. For bleaching of clothes in the laundry $${H_2}{O_2}$$ is being used instead of $$C{l_2}$$ which give better results, is not harmful and saves a lot of water.
89.
Phosphate pollution is caused by
A
sewage and agricultural fertilizers
B
weathering of phosphate rocks only
C
agricultural fertilizers only
D
phosphate rocks and sewage
Answer :
sewage and agricultural fertilizers
Phosphate pollution is caused by sewage and agricultural fertilizers.
90.
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
(i), (iv) and (v)
B
(iii) only
C
(ii) only
D
(ii) and (v)
Answer :
(ii) only
The irritant red haze in the traffic and congested places is due to presence of oxides of nitrogen.