Chapter 12: Air

Question 1

What does the air consist of and their percentages

Answer 1

1. Nitrogen: 78%
2. Oxygen: 21%
3. Other gases: 1%

Question 2

Name the common air pollutants and their sources

Answer 2

1. Carbon monoxide - Produced from incomplete combustion of carbon-containing substances like petrol
2. Oxides of nitrogen - Lightning activity, combustion in engine, react with water to form acidic rain which corrodes building and harm aquatic life
3. Sulphur dioxide - Volcanic eruption, burning of fossil fuels, vehicle exhaust fumes
4. Ozone, methane, unburnt hydrocarbons

Question 3

Explain the effects of the air pollutants

Answer 3

1. Carbon monoxide
   1) Reacts with haemoglobin in the blood, which reduces the ability of haemoglobin to transport oxygen to the rest of the body

2) Causes headache, fatigue, breathing difficulties and even death

2. Sulfur dioxide and oxides of nitrogen
   1) Irritate the eyes and lungs and cause breathing difficulties
   2) React with water to form acidic rain which corrodes buildings and harms aquatic life and plants