#"H"_3"CCH"_2"CH"_2"CH"_2"CH"_3#, #"n-pentane"#, #"H"_3"CCH(CH"_3")CH"_2"CH"_3#, #"isopentane"#, #"C(CH"_3")"_4#, #"neopentane"#.
These have respective boiling points of #36# #""^@C#, #30# #""^@C#, and #9.5# #""^@C#; this is a fairly wide boiling point range for #C_5H_12#. Clearly, the more branched the isomer, the less opportunity there are for chain-chain interactions, and the less intermolecular interaction, the lower the boiling point. And thus even for a short-chain hydrocarbon, isomerism affects volatility.
