Hydrocarbon definition and formula


Content – Oil & Gas


The main chemical components of fossil fuels such as oil and gas are hydrocarbons. Hydrocarbons belong to a group of chemical substance composed only by Carbon and Hydrogen atoms.

Fossil fuels definition

The tables below display a group of hydrocarbons named Alkanes, including their chemical formula and their phase at atmospheric pressure and 20° C

The lightest components Methane CH4 boils at -161° C while Hexane C6H14boils at 69°C.

Hydrocarbon Formula Phase Category
Methane CH4 Gas
Ethane C2H6 Gas
Propane C3H8 Gas
Butane C4H10 Gas
Pentane C5H12 Liquid Gasoline/Naphtha
Hexane C6H14 Liquid Gasoline/Naphtha
Heptane C7H16 Liquid Gasoline/Naphtha
Octane C8H18 Liquid Gasoline
Nonane C9H20 Liquid Gasoline
Decane C10H22 Liquid Gasoline
Hendecane C11H24 Kerosene/Paraffin
Dodecan C12H26 Kerosene/Paraffin/Diesel
Tridecan C13H28 Kerosene/Paraffin/Diesel
Tetradecan C14H30 Kerosene/Paraffin/Diesel
Pentadecane C15H32 Kerosene/Paraffin/Diesel
Hexadecane C16H34 Kerosene/Diesel
Heptadecane C17H36 Kerosene/Diesel
Octadecane C18H38 Kerosene/Diesel
Nonadecane C19H40 Oil/Waxes/Diesel
Elcosane C20-C42 Oil/Waxes/Diesel
C20-C50Hn Oil/Waxes/Lubricants
C20-C70Hn Heavy Oils
>C70Hn Asphalt/Bitumen

Even if coal is not a hydrocarbon but still a fossil fuel, a brief description is included.

Coal primarily consists of carbon together with minerals as clay and quarts transformed from plants.

Partly transformed material from plants (Kerogen). Around 50% Carbon

Brown, soft coal, more than 70% Carbon, transforms below 100° C

Black coal, more than 70% Carbon, transforms between 100° C -200° C

Black coal, more than 70% Carbon, transforms between 200° C -300° C