Butane is a hydrocarbon with formula C4H10, that is, an alkane with four carbon atoms. The term may refer to any of two structural isomers, or to a mixture of them: Common name normal butaneunbranched butanen-butane isobutanei-butane IUPAC name butane methylpropane Moleculardiagram Skeletaldiagram In the IUPAC nomenclature, however, butane refers only to the unbranched n-butane isomer; the other one being called "methylpropane". Butanes are highly flammable, colorless, odorless, easily liquefi… (More on N-butane)