What is "isopentane"

n. (context organic compound English) The aliphatic hydrocarbon 2-methylbutane; isomeric with pentane and neopentane.

Isopentane, C H, also called methylbutane or 2-methylbutane, is a branched-chain alkane with five carbon atoms. Isopentane is an extremely volatile and extremely flammable liquid at room temperature and pressure. 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. It is 1% or less of natural gas.