Properties & Effects of Atmospheric Pollutants (AQA GCSE Chemistry)

Atmospheric pollutants

Carbon monoxide poisoning

• Carbon monoxide is an extremely poisonous gas as it combines with haemoglobin in blood and prevents it from carrying oxygen

• It is particularly dangerous as it is colourless and odourless, making it difficult to detect

• A lack of oxygen supply to the brain can lead to fainting, coma or death

Why is releasing particulates a problem?

• Solid carbon particles (or particulates) released from incomplete combustion clump together to form soot which gradually falls back to the ground

• Particulates can cause several problems:

  • If they are inhaled they can damage the lungs and cause respiratory problems

  • They can cover buildings and statues, making them look unclean and accelerating corrosion

  • They can reflect sunlight back into space reducing the amount of light reaching the earth, this is called global dimming

Statues and monuments in very polluted areas become blackened over time from soot

Sulfur Dioxide

• Sulfur dioxide is a colourless, pungent smelling gas that is a major air pollutant responsible for acid rain

• The sulfur dioxide released mixes with clouds and readily dissolves in rainwater

• SO₂ is a non-metal oxide so it forms an acidic solution in water, hence forming acid rain, H₂SO₄

• Acid rain causes corrosion to metal structures, buildings and statues made of carbonate rocks

• It causes damage to aquatic organisms, pollutes crops and water supplies, and irritates lungs, throats and eyes

How acid rain is formed

Oxides of sulfur and nitrogen contribute to the formation of acid rain

Oxides of Nitrogen

• Oxides of nitrogen come largely from vehicle exhausts and also contribute to acid rain

• They are produced when nitrogen and oxygen react at high temperatures which are reached in a vehicle engine

• Aside from acid rain, oxides of nitrogen produce photochemical smog and breathing difficulties, in particular for people suffering from asthma