There are three structural isomers possible for the molecular formula C5H12. They are:1. n-Pentane:Structure: CH3-CH2-CH2-CH2-CH3Name: n-Pentane normal pentane 2. Isopentane 2-methylbutane :Structure: CH3 2CH-CH2-CH3Name: Isopentane 2-methylbutane 3. Neopentane 2,2-dimethylpropane :Structure: CH3 3C-CH3Name: Neopentane 2,2-dimethylpropane These three isomers have the same molecular formula but different structural arrangements of carbon and hydrogen atoms.