General Formula: CnH2n+2, n = 1, 2, 3, …
Functional Group:
No Functional Group
First 3 Members:
- Alkane are the simplest family of hydrocarbons – compounds containing carbon and hydrogen only.
- They only contain carbon-hydrogen bonds and carbon-carbon single bonds.
- Alkanes are saturated hydrocarbon
Nomenclature of Alkanes
- Nomenclature = Naming method.
- All organic carbon compounds are named according to the number of carbon in the molecule.
- The name is made up of two parts: the stem and the suffix.
- The stem tells the number of carbon atoms
- The suffix tells the homologous series of the compound.
Example:
Ethane is an alkane, the stem “eth” tell us that it has 2 carbon in the molecule, and the suffix “ane” indicates that it is a member of the alkanes homologous series.
The table below shows the naming code for the stem. In SPM, You will need to remember the codes for the number of carbon atoms in a chain up to 6 carbons.
| No of carbons | Code | No of carbons | Code |
| 1 | meth | 7 | hept |
| 2 | eth | 8 | oct |
| 3 | prop | 9 | non |
| 4 | but | 10 | dec |
| 5 | pent | 11 | hendec |
| 6 | hex | 12 | dodec |
Name of the First 8 Alkanes
The table below shows the molecular formula and name of the first 8 members of alkanes.
| Number of Carbon | Molecular Formula | Name |
|---|---|---|
| 1 | CH4 | Methane |
| 2 | C2H6 | Ethane |
| 3 | C3H8 | Propane |
| 4 | C4H10 | Butane |
| 5 | C5H12 | Pentane |
| 6 | C6H14 | Hexane |
| 7 | C7H16 | Heptane |
| 8 | C8H18 | Octane |