Butane is the n = 4 case in the series of
alkane single-bond chain
hydrocarbons, each made up of n
carbon atoms and 2n+2
hydrogen atoms. The two forms of butane are n-butane and 2-
methyl-
propane. An
unofficial name for the second form of butane is isobutane, because it is the one and only
isomer of the chemical.
n-butane boils at -0.5° C (31.1° F); isobutane boils at -11.7° C (10.9° F).