paraffin series). The general formula for this series is CnH 2 n+2, where n is the
number of carbons in the molecule. Table 14 provides some essential information
about this series. Since many other organic structures use the stem of the alkane
names, you should learn these names and structures well. Notice that, as the
number of carbons in the chain increases, the boiling point also increases. The
first four alkanes are gases at room temperature; the subsequent compounds are
liquid, then become more viscous with increasing length of the chain.
TIP
Alkanes are CnH 2 n (^) + 2. They are homologous.
Since the chain is increased by a carbon and two hydrogens in each
subsequent molecule, the alkanes are referred to as a homologous series.
The alkanes are found in petroleum and natural gas. They are usually
extracted by fractional distillation, which separates the compounds by varying the
temperature so that each vaporizes at its respective boiling point.
TIP
Learn the names of the first 10 alkanes.Table 14. The Alkanes