250+ TOP MCQs on Air Pollution – Sources and Answers

Environmental Science Multiple Choice Questions on “Air Pollution – Source”.

1. Which of these is NOT a primary pollutant?
a) Carbon monoxide
b) Carbon dioxide
c) Ground level ozone
d) Oxygen

Answer: d
Clarification: Ozone is not a primary pollutant since it is formed by the photo-chemical reaction of oxygen with the UV rays and not directly discharged into the atmosphere by a source.

2. What percentage of pollutants is gaseous in nature?
a) 75%
b) 80%
c) 99.9%
d) 90%

Answer: d
Clarification: Nearly 90% of the air pollutants are gases.

3. Which of the following is an inorganic pollutant?
a) Carbon monoxide
b) Carbonyl compounds
c) Aromatic hydrocarbons
d) None of the mentioned

Answer: a
Clarification: Organic pollutants are those which primarily contain hydrogen and carbon. Carbon Monoxide is inorganic since it does not contain hydrogen.

4. Which of these belongs to the category of criteria pollutants?
a) Ozone
b) Lead
c) Carbon monoxide
d) All of the mentioned

Answer: d
Clarification: Criteria pollutants are those pollutants which are classified and standardized because of their high potency to cause harm.

5. Which of the following are classified as major sources to air pollution?
a) Fuel consumption by local citizens
b) Sewage treatment plants
c) Dry cleaning and laundries
d) None of the mentioned

Answer: b
Clarification: Sewage treatment plants pose as a major contributor to air pollution because of the discharge of gases such as methane, oxides of sulphur and nitrogen.

6. Which is the most abundant hydrocarbon in the atmosphere?
a) Methane
b) Carbonyl sulphide
c) Ethane
d) None of the mentioned

Answer: a
Clarification: Methane is highly abundant since it is released during decaying process of dead matter.

7. What does the abbreviation VOC stand for?
a) Versatile Oxygenated Compounds
b) Volatile Oxygenated Compounds
c) Volatile Organic Carbons
d) Volatile Organic Compounds

Answer: d
Clarification: VOC is used as an abbreviation for Volatile Organic Compounds.

8. What is the range of vapour pressure of VOCs?
a) High vapour pressure
b) Low vapour pressure
c) Depends on the concentration of VOCs
d) Depends on the type of VOCs

Answer: b
Clarification: Generally, VOCs have low vapour pressure enabling them to exist in atmosphere as gases.

9. Which is the largest-volume manufactured organic chemical?
a) Ethylene
b) Ethane
c) Formaldehyde
d) Carbonic acid

Answer: a
Clarification: Ethylene. It is not toxic to human beings or animals, but has adverse effects on plants when present at very small concentrations as well and hence acts as an air pollutant.

10. What does PAH stand for in terms of organic chemistry?
a) Polynuclear Aromatic Hydrocarbons
b) Polyethylene Acetic Hydride
c) Polycyclic Acetic Hydrocarbons
d) Polynuclear Aromatic Hydrides

Answer: a
Clarification: Polynuclear Aromatic Hydrocarbons such as Benzo-(a)-pyrene, is a type of pollutant that is released from a burning cigarette.