Test yourself on Combustion with exam style questions, marked instantly.
Flashcards that come back just before you would forget them.
A revision plan that remembers what you know and shows what to do next.
See which topics you have nailed and which need another look.
Quiz yourself on CombustionGet your flashcardsBuild my revision planTrack my progress🌫️ Air Pollutants from Burning Fuels
Burning fossil fuels produces more than just CO₂ and water. Three additional pollutants are regularly examined at GCSE: sulfur dioxide, nitrogen oxides, and particulates.
| Pollutant | How it forms | Environmental and health effects |
|---|---|---|
| Sulfur dioxide (SO₂) | Formed when fuels containing sulfur impurities are burned: S + O₂ → SO₂ | SO₂ dissolves in rain → sulfuric acid → acid rain. Damages limestone buildings, kills freshwater fish, strips leaves from trees |
| Nitrogen oxides (NOₓ) | N₂ and O₂ in the air react at the high temperatures inside engines: N₂ + O₂ → 2NO | Cause acid rain and photochemical smog; trigger asthma and lung damage in humans |
| Particulates (soot) | Tiny carbon particles from incomplete combustion of fuels | Cause respiratory problems, blacken buildings, and contribute to global dimming by reflecting sunlight |
Key distinction to remember: SO₂ comes from sulfur in the fuel. NOₓ comes from nitrogen in the air — the high engine temperature causes this normally unreactive gas to react.
Make this stick
Signing in gives access to all PrepWise features.