hydrocarbons

Organic compounds consisting of carbon and hydrogen are called hydrocarbons. They are the simplest form of the organic compounds. Hydrocarbons are regarded as the parent family of organic compounds because other various organic compounds may be synthesized from hydrocarbons through chemical process by replacement of one or many hydrogen atoms by functional groups.
The main sources of organic compounds are coal and petroleum since they are byproducts of living organisms like plant and animals i.e. both are considered to be of biological origin. Petroleum is commonly called rock oil. In Greek, Petra stands for rock and oleum stands for oil. Thus coal and petroleum are naturally occurring sources of hydrocarbons. Lower hydrocarbons like methane, ethane, propane etc are present in natural gases which are mainly obtained from petrol. Coal is the chief sources of aromatic hydrocarbons. Thus naturally occurring fossils like petroleum and coal are the major sources of different hydrocarbons. Aliphatic hydrocarbons are mostly obtained from petroleum whereas aromatic hydrocarbons are extracted from coal.