This set of Pollution Control Multiple Choice Questions & Answers (MCQs) focuses on “Characteristics of Gaseous Pollutants”.
1. Which of the following is a product of the oxidation of sulphur dioxide?
a) It does not oxidise
b) Sulphur trioxide
c) Sulphuric acid
d) It gets reduced
View Answer
Explanation: Sulphur dioxide oxidises in the atmosphere to become sulphur trioxide. Sulphuric acid formation occurs due to the hydration of sulphur trioxide. Sulphur dioxide does not get reduced in the atmosphere.
2. What is the hydration product of sulphur dioxide?
a) Sulphurous acid
b) Sulphuric acid
c) It does not get hydrated
d) Sulphur trioxide
View Answer
Explanation: Sulphur dioxide is soluble in water and reacts with it to produce sulphurous acid. Sulphur trioxide is the oxidation product of sulphur dioxide, and the production of sulphates occurs from sulphuric acid.
3. Which of the following is a reduction product of sulphur dioxide in the atmosphere?
a) Sulphur oxide
b) Sulphur trioxide
c) It does not get reduced
d) Sulphuric acid
View Answer
Explanation: Sulphur dioxide does not get reduced in the atmosphere. On the other hand, it does get oxidised in the atmosphere to produce sulphur trioxide. Sulphur trioxide gets further oxidised to sulphuric acid.
4. Which of the following statements about sulphur dioxide is false?
a) It has a pungent odour
b) It is the primary sulphur oxide released from pollution sources
c) It is colourless
d) It is reddish-brown in colour
View Answer
Explanation: Sulphur dioxide has a pungent odour and is colourless. Sulphur dioxide the primary sulphur oxide released from sources of pollution. Nitrogen dioxide is reddish-brown in colour.
5. Sulphuric acid is formed by the hydration of which of the following gases?
a) Sulphur dioxide
b) Sulphur trioxide
c) Hydrogen sulphide
d) Sulphur oxide
View Answer
Explanation: Sulphur trioxide reacts with water to produce sulphuric acid in the atmosphere. Sulphur dioxide hydration produces sulphurous acid, which is a weak acid. The other options are not applicable.
6. Why are sulphuric acid concentrations so low in the atmosphere when compared to its emissions?
a) It cannot be detected
b) Its concentrations are high
c) Its emissions are low
d) Its retention time is low
View Answer
Explanation: The retention time (which estimates the time for which a gas is retained in the atmosphere) of sulphur dioxide in the atmosphere is low. It either gets converted to sulphates (aerosols), or acid and washes out as rain.
7. What percent of sulphur dioxide concentration is sulphur trioxide concentration in emission sources?
a) 2%
b) 8%
c) 16%
d) 24%
View Answer
Explanation: Sulphur dioxide concentration in emissions is much higher than sulphur trioxide. Sulphur trioxide emission ranged from 1% to 5% of total sulphur dioxide concentration. Among the given options, only 2% falls in this range.
8. Which of the following nitrogen oxides is not present in significant quantities in the atmosphere?
a) NO
b) NO2
c) N2O3
d) N2O
View Answer
Explanation: There are about 6 or 7 prominent nitric oxides, but only about 3 of them are present in significant quantities. Both NO and NO2 are present in significant quantities. Ofthe listed options, nitrous oxide does not get categorised as a pollutant.
9. Which of the following nitrogen oxides does not get categorised as an air pollutant?
a) Nitric oxide
b) Nitrogen dioxide
c) Dinitrogen trioxide
d) Nitrous oxide
View Answer
Explanation: Except for dinitrogen tetraoxide, all the given oxides of nitrogen are present in the atmosphere in significant quantities. Of these, nitric oxide and nitrogen dioxide get categorised as air pollutants.
10. Nitric oxide is oxidised to which of the following gases in the atmosphere?
a) NO
b) Nitrogen dioxide
c) Nitrous oxide
d) Nitrogen trioxide
View Answer
Explanation: Nitric oxide oxidises to nitrogen dioxide in the atmosphere. This reaction happens in the presence of sunlight. This conversion is also a reason why nitric oxide concentration in the atmosphere is low.
11. Which of the following statements about nitrogen dioxide is untrue?
a) It is reddish-brown in nature
b) It has an odour
c) It is odourless
d) It is formed in the atmosphere
View Answer
Explanation: Nitrogen dioxide is formed in the atmosphere by the oxidation of nitric oxide in the presence of sunlight. It is reddish-brown in colour and has a pungent odour, and hence, is not odourless.
12. Which of the following nitrogen oxides has a low reactivity in the atmosphere?
a) Nitrous oxide
b) Nitrogen dioxide
c) Nitric oxide
d) Sodium nitrate
View Answer
Explanation: Both nitric oxide and nitrogen dioxide have high reactivity in the atmosphere, especially in the presence of sunlight. On the other hand, nitrous oxide is relatively less reactive than the other listed oxides.
13. Which of the following is true about nitric oxide?
a) It is yellowish-brown in colour
b) Its primary source is the combustion of fuel
c) It has a pungent odour
d) It is not reactive in the atmosphere
View Answer
Explanation: The primary source of nitric oxide in the atmosphere is the combustion of fuels. Nitric oxide is colourless and odourless in nature. Nitric oxide is highly reactive in the atmosphere, so this statement is false.
14. Which of the following pollutants are not produced when NOX react in the atmosphere?
a) Ozone
b) Acid rain
c) Water vapour
d) Particulate matter
View Answer
Explanation: Nitrogen oxides are highly reactive in the atmosphere and produce various other pollutants because of this. Acid rain, ozone, and particulate matter are all examples of such secondary pollutants.
15. Of the given options, which one has the least concentration in the atmosphere?
a) Particulate matter
b) Sulphur dioxide
c) Carbon monoxide
d) Nitrogen dioxide
View Answer
Explanation: Though all air pollutants have a significant concentration in the atmosphere, their relative concentration varies. Accordingly, the concentration of nitrogen dioxide is the least, while the concentration of carbon monoxide is the highest.
Sanfoundry Global Education & Learning Series – Pollution Control.
To practice all areas of Pollution Control, here is complete set of 1000+ Multiple Choice Questions and Answers.
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