Butane is a flammable, colorless gas that follows propane in the alkane series. Butane is also called n-butane, with the “n” designating it as normal butane, the straight chain isomer. Butane’s other isomer is isobutane. The chemical name of isobutane is 2-methylpropane. Isomers are different compounds that have the same molecular formula. Normal butane and isobutane are two different compounds, and the name butane is used collectively to denote both n-butane and isobutane; the names n-butane and isobutane are used to distinguish properties and chemical characteristics unique to each compound.
Butane, along with propane, is a major component of liquefied petroleum gas . It exists as a liquid under moderate pressure or below 0℃ at atmospheric pressure, which makes it ideal for storage and transportation in liquid form.