Methane is a colourless, odourless gas which is lighter than air. It is formed by the decomposition of organic carbons under anaerobic conditions and is commonly found in or near swamps and wetland areas, peat deposits, woodwastes such as hogfuel, or in the area of old landfills.
The rate and rapidity of methane production depends on many factors, including the amount of rainfall penetrating to and through the organic matter, the temperature, and the type of the organic materials. Changes in these conditions, even many years after the organic matter has been placed on a site, can result in marked changes in the rate of methane production.
Formula : CH4
Molecular weight : 16.043 g/mol
Physical Properties of Methane
- Methane is an odourless, colourless, tasteless gas.
- Melting point : -182.5 °C
- Critical Temperature : -115.8°F
- Critical Pressure: 673.1 psia
- It is lighter than air.
- It is a non-polar molecule and is insoluble in water.
- It dissolves in non-polar solvents like alcohol, carbon
tetrachloride, etc.
- It is a renewable source of natural gas since it comes from decaying garbage.
- Methane burns in air with a blue flame. We have seen earlier that
in sufficient amount of oxygen, methane burns to give carbon dioxide
and water. In insufficient oxygen it gives out carbon monoxide.
Methane produces a good amount of heat when it undergoes combustion.
This is the reason why it is used as fuel.
- Methane is quite unreactive, except with fluorine, chlorine, etc.
With these it undergoes substitution reactions.
- Methane undergoes oxidative pyrolysis to form carbon monoxide. It
is formed by reaction of methane with methyl radical which further
reacts to formaldehyde. Then formaldehyde reacts to formal radical
to form carbon monoxide. · The strength of carbon hydrogen
covalent bonds in strongest among all hydrocarbons.
- It also undergoes halogenation.






