Combustion is the process of burning of a substance in the presence of air or oxygen with the liberation of heat and light. Substances that burn in air or oxygen to produce heat and light are called combustible substances. They are also known as fuel. Substances that do not burn in air or oxygen are called non-combustible substances. Products of combustion depend upon the nature of the combustible substance. Most of the fuels that we use are hydrocarbons. when these hydrocarbons (present in fuel) burn completely, the products formed are:
