Chemistry 9th Chap 11 : Topic 2 - Maryam Publications

Chemistry Chapter 11 : Topic 2

Sources of Air Pollutants

1 / 20

Which of the following is the major source of carbon dioxide in the atmosphere?

A) Decomposition of plants in marshes

B) Reaction of nitrogen and oxygen in air

C) Incomplete combustion of hydrocarbons in engines

D) Complete combustion of carbon-containing fuels such as coal and petrol

2 / 20

Carbon monoxide is mainly produced when:

A) Fuel undergoes nuclear decomposition

B) Fuel burns completely in excess oxygen

C) Fuel burns incompletely due to insufficient oxygen supply

D) Carbon dioxide reacts with oxygen

3 / 20

Particulate matter in air pollution is mainly produced from:

A) Incomplete combustion of carbon-containing fuels

B) Condensation of water vapor

C) Complete combustion of fuels

D) Photosynthesis in plants

4 / 20

Methane in the atmosphere is mainly released from:

A) Reaction of nitrogen and oxygen in engines

B) Industrial chemical reactions

C) Burning of petrol engines

D) Decomposition of vegetation and animal digestion

5 / 20

Oxides of nitrogen are mainly produced by:

A) Evaporation of fuels

B) Photosynthesis in plants

C) Car engines at high temperature

D) Burning of plastics at home

6 / 20

Sulfur dioxide is mainly released from:

A) Burning of sulfur-free fuels

B) Combustion of fossil fuels containing sulfur compounds

C) Electrolysis of water

D) Decomposition of nitrogen compounds

7 / 20

Ground level ozone is formed due to:

A) Direct emission from factories

B) Burning of hydrogen fuel

C) Decomposition of methane

D) Reaction of nitrogen oxides and VOCs in sunlight

8 / 20

Which gas is a primary pollutant but also contributes to secondary pollution?

A) Nitrogen oxides

B) Helium

C) Nitrogen

D) Oxygen

9 / 20

Volatile organic compounds (VOCs) mainly come from:

A) Solid rock decomposition

B) Pure oxygen cylinders

C) Fuel evaporation and industrial emissions

D) Natural rainfall

10 / 20

Which process contributes BOTH carbon monoxide and particulates?

A) Electrolysis of water

B) Complete combustion of LPG

C) Incomplete combustion of carbon-based fuels

D) Photosynthesis in green plants

11 / 20

Why is car exhaust considered a major source of air pollution?

A) It releases only oxygen.

B) It emits CO, NOₓ, particulates and VOCs.

C) It produces only water vapor.

D) It releases nitrogen only.

12 / 20

Methane is classified as an air pollutant mainly because it:

A) is a greenhouse gas contributing to climate change

B) is produced by oxygen combustion

C) is heavier than oxygen

D) reacts with water to form acids

13 / 20

Which of the following is a SECONDARY pollutant?

A) Particulate matter

B) Carbon monoxide

C) Sulfur dioxide

D) Ground level ozone

14 / 20

Sulfur dioxide pollution is most closely associated with:

A) Burning of fossil fuels in power plants

B) Electric vehicles

C) Solar energy production

D) Water electrolysis

15 / 20

Which combination of gases leads to photochemical smog formation?

A) Oxygen and nitrogen

B) Nitrogen oxides and VOCs

C) Carbon dioxide and methane

D) Hydrogen and helium

16 / 20

Decomposition of vegetation mainly contributes to the release of:

A) Oxygen

B) Sulfur dioxide

C) Carbon monoxide

D) Methane

17 / 20

Which is NOT a direct source of air pollution?

A) Natural decomposition of waste

B) Photosynthesis in plants

C) Industrial combustion

D) Vehicle engines

18 / 20

Why are nitrogen oxides considered harmful pollutants?

A) They contribute to smog and acid rain formation.

B) They are inert gases.

C) They are only naturally produced.

D) They reduce oxygen levels in water only.

19 / 20

Which fuel is MOST likely to produce sulfur dioxide on burning?

A) Coal containing sulfur compounds

B) Pure hydrogen

C) Natural gas without impurities

D) Oxygen gas

20 / 20

The main reason incomplete combustion occurs in engines is:

A) Presence of helium

B) Insufficient oxygen supply

C) Excess oxygen supply

D) Low nitrogen content

Your score is

0%