Question

What are the molecular formula, the structural formula, the condensed structural formula, and the abbreviated line formula for pentane?

Answer 1

The name pentane can be used for any of the three structural isomers that share the molecular formula `C_5H_12`. In IUPAC nomenclature however the term pentane is used exclusively for n-pentane, the unbranched isomer of the group.

The molecular formula of pentane, or n-pentane, is `C_5H_12`.

The structural formula will be `CH_3CH_2CH_2CH_2CH_3`.

The condensed structural formula will be `CH_2(CH_2)_3CH_3`.

The skeletal structure, also called bond-line notation, for n-pentane will be

Pentane's two other isomers are called isopentane (or 2-methylbutane)

and neopentane (or 2,2-dimethylpropane)