Combustion: definition in chemistry
Combustion: A fast reaction between a fuel and oxygen that releases energy as heat and usually light. Burning is the everyday word for it.
Complete combustion of a hydrocarbon fuel in plenty of oxygen produces carbon dioxide and water. When oxygen is limited, incomplete combustion also produces carbon monoxide, a poisonous gas, and soot (carbon). Combustion needs fuel, oxygen and enough heat to start it, so removing any one of the three, the idea behind the fire triangle, puts a fire out.
Examples
- Methane burning: CH₄ + 2O₂ → CO₂ + 2H₂O
- Gasoline burning in a car engine
- Magnesium ribbon burning with a brilliant white flame to form MgO
- A candle burning its wax vapor in air
On the periodic table
Most fuels are compounds of carbon and hydrogen, and they burn by reacting with oxygen from group 16 to form carbon dioxide and water.