2-Methylbutane

Isopentane, also called methylbutane or 2-methylbutane, is a branched-chain saturated hydrocarbon (an alkane) with five carbon atoms, with formula C
5
H
12
or CH(CH
3
)
2
(C
2
H
5
)
.

Isopentane is an extremely volatile and extremely flammable liquid at room temperature and pressure. It is also the least dense liquid at standard conditions.[citation needed] The normal boiling point is just a few degrees above room temperature and isopentane will readily boil and evaporate away on a warm day.

Isopentane is commonly used in conjunction with liquid nitrogen to achieve a liquid bath temperature of −160 °C. Natural gas typically contains 1% or less isopentane,but it is a significant component of natural gasoline.[4]