For a five-carbon alkane, there are three possible structural isomers. Their names and structures are as follows:1. n-Pentane straight-chain isomer Structure: CH3-CH2-CH2-CH2-CH32. Isopentane 2-methylbutane Structure: CH3-CH CH3 -CH2-CH33. Neopentane 2,2-dimethylpropane Structure: CH3-C CH3 2-CH3