Butane

Names Preferred IUPAC nameSystematic IUPAC nameOther names Identifiers 969129 ChEBIChEMBLChemSpiderECHA InfoCard100.003.136EC NumberE numberE943a (glazing agents, ...)1148 KEGGMeSHbutaneRTECS numberUNIIUN number1011 Properties C₄H₁₀Molar mass58.124 g·mol Appearance Colorless gas OdorGasoline-like or natural gas-like Density2.48 kg/m (at 15 °C (59 °F)) Melting point−140 to −134 °C; −220 to −209 °F; 133 to 139 K Boiling point−1 to 1 °C; 30 to 34 °F; 272 to 274 K 61 mg/L (at 20 °C (68 °F)) log P2.745 Vapor pressure~170 kPa at 283 K 11 nmol Pa kg −57.4·10 cm/mol Thermochemistry 98.49 J/(K·mol) −126.3–−124.9 kJ/mol −2.8781–−2.8769 MJ/mol Hazards GHS labelling: DangerH220P203, P210, P222, P280, P377, P381, P403NFPA 704 (fire diamond) Flash point−60 °C (−76 °F; 213 K) 405 °C (761 °F; 678 K) Explosive limits1.8–8.4% NIOSH (US health exposure limits): none TWA 800 ppm (1900 mg/m) 1600 ppm Related compounds PerfluorobutaneSupplementary data page Butane (data page)

Butane () is an alkane with the formula C₄H₁₀. Butane exists as two isomers, n-butane, CH₃CH₂CH₂CH₃ and iso-butane, (CH₃)₃CH. Both isomers are highly flammable, colorless, easily liquefiedgases that quickly vaporize at room temperature and pressure. Butanes are a trace component of natural gases, which contain higher concentrations of other hydrocarbons such as propane, ethane, and especially methane. Liquefied petroleum gas is a mixture of propane and some butanes.

The name butane comes from the root but- (from butyric acid, named after the Greek word for butter) and the suffix -ane (for organic compounds).