Sources of Sulfur Dioxide

Specification Point 8.11:
  • Explain how impurities in some hydrocarbon fuels result in the production of sulfur dioxide
  • SO2 is produced during the combustion of fossil fuels.
  • Sulfur impurities present in the fuels react with oxygen during combustion to produce sulfur dioxide.
  • Sulfur dioxide is also released from sulfide ores e.g: zinc blende (ZnS) in the extraction of zinc:

2ZnS + 3O2 → 2ZnO + 2SO2

Acid Rain

Specification Point 8.12:
  • Explain some problems associated with acid rain caused when sulfur dioxide dissolves in rain water
  • The sulfur dioxide released mixes with clouds and dissolves in rainwater.
  • SO2 is a non-metal oxide, so it forms an acidic solution in water, hence forming acid rain.
  • 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.

Oxides of Nitrogen

Specification Point 8.13:
  • Explain why, when fuels are burned in engines, oxygen and nitrogen can react together at high temperatures to produce oxides of nitrogen, which are pollutants
  • Oxides of nitrogen are produced in the reaction of nitrogen with oxygen at high temperatures and pressure in car engines and high temperature furnaces and as a product of bacterial action in soil.
  • Nitric oxides produce acid rain with similar effects as SO2 as well as producing photochemical smog and causing breathing difficulties, in particular for people suffering from asthma.

Acid Rain Lake, Edexcel GCSE Chemistry

The unfortunate effect of acid rain as it lowers lake water pH to dangerous levels

Edexcel GCSE Chemistry Notes

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Morgan Curtin Chemistry

Author: Morgan

Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.