The alkanes are saturated hydrocarbons.

Hydrocarbons are compounds which contain only hydrogen and carbon.

Alkanes are described as saturated because their carbon atoms are joined by C–C single bonds. They do not contain C=C bonds.

The general formula for the alkanes is CnH2n+2.


Decane is an alkane. A molecule of decane contains 10 carbon atoms. Predict the molecular formula of decane.

n = 10

∴ 2n + 2 = (2 × 10) + 2 = 20 + 2 = 22

Formula: C10H22

The table shows the first four alkanes.

Gas table