An alkane has a molecular mass of 72 . Give structure of all the possible isomers along with their IUPAC names.

Explanation

Let the alkane be `C_nH_(2n_2)`. Its molecular mass `=12n+(2n+2)=14n+2`.
`therefore 14n+2=72` thus n=5 and hence the alkane is `C_5H_(12)`.
The isomers of the alkane `C_5H_(12)` are-
`underset("pentane")(CH_3-CH_2-CH_2-CH_2-CH_3)`
`CH_3-underset(CH_3)underset(|)CH-CH_2-CH_3, CH_3-overset(CH_3)overset(|)underset(CH_3)underset(|)C-CH_3`
2-methylbutane 2,2 -dimethylpropane