Combustion - Definition and Overview

Combustion or burning is an exothermic reaction between a substance and a gas to release heat. Combustion normally occurs in oxygen (often in the form of gaseous O₂) to form oxides, However, combustion can also take place in other gases like chlorine.

The products of such reactions usually include water (H₂O) as well as carbon monoxide (CO) or carbon dioxide (CO₂), or both. Other byproducts, such as partially reacted fuel and elemental carbon (C), may generate visible smoke and soot.

Rapid combustion

Rapid combustion is a form of combustion in which large amounts of heat and light energy are released.

Slow combustion

Slow combustion is a form of combustion which takes place at low temperatures. Respiration is slow combustion.

Chemical equation

Generally, the chemical equation for combusting a hydrocarbon in oxygen (such as octane) is as follows:

C_xH_y + (x + y/4)O₂ → xCO₂ + (y/2)H₂O

For example, the burning of propane is:

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

See also

• Heat of combustion
• spontaneous combustion
• fire
• deflagration
• detonation
• pyrolysis
• phlogiston
• pyrophoric
• internal combustion engine
• measurement techniques
  • Calorimeter
  • Particle Image Velocimetry
  • Laser Doppler Velocimetry
  • Laser Induced Fluorescence
  • Coherent Anti-Stokes Raman Spectroscopy (CARS)