Last seen: May 1, 2022
Correct answer: (b) NO and freons Explanation: NO and freons are responsible for ozone layer depletion.
Correct answer: (b) Nitrogen dioxide Explanation: NO2 forms a part of photochemical smog.
Correct answer: (d) Enhanced growth of algae
Correct answer: (b) CFC > N2O > CH4 > CO2 Explanation: CFC > N2O > CH4 > CO2
Correct answer: (b) CH2 = CH2 Explanation: Ethanal is commercially prepared by one step oxidation of ethene in the presence of ionic catalyst in a...
Correct answer: (b) SO3 is more harmful air pollutant than SO2 Explanation: SO3 is more harmful pollutant than SO2.
Correct answer: (b) Liquid CO2 Explanation: Replacement of earlier used tetra-chloroethene as solvent for dry cleaning by liquid CO2 results in le...
Correct answer: (b) Reduce the use and production of hazardous chemicals. Explanation: Green chemistry may be defined as the programme of developi...
Correct answer: (b) 10 ppm Explanation: In cold water, dissolved oxygen can reach a concentration upto 10 ppm, whereas oxygen in air is about 200,...
Correct answer: (a) microbes and organic matter. Explanation: BOD is connected with microbes and organic matter.
Correct answer: (d) H2SO4 Explanation: Acid rain contains H2SO4 > HNO3 > HCl.
Correct answer: (a) polycyclic aromatic hydrocarbons Explanation: PAH (Poly Aromatic Hydrocarbon)
Correct answer: (c) Methane Explanation: Most abundant hydrocarbon pollutant is methane.
Correct answer: (c) troposphere Explanation: Air pollution greatly affect the troposphere.
Correct answer: (a) more than 17 ppm. Explanation: Water sample is reported to be highly polluted if BOD value of sample is more than 17 ppm.
Correct answer: (c) O3 Explanation: Chemical pollutants in photochemical smog are nitrogen oxides (NO and NO2), volatile organic compounds, ozone ...
Correct answer: (d) Decrease in D.O. Explanation: Decrease in D.O causes death of fish.
Correct answer: (d) Mercury Explanation: Minamata is caused by Hg poisoning.
Correct answer: (a) slightly lower than that of rain water without thunderstorm. Explanation: Normal rain water has pH 5.6. Thunderstorm results i...
Correct answer: (a) sewage and agricultural fertilizers Explanation: Phosphate pollution is caused by sewage and agricultural fertilizers.