Simplest alkyne, CH. A colourless, flammable, explosive gas, it is used as a fuel in welding and cutting metals and as a raw material for many organic compounds and plastics. It is produced by reaction of water with calcium carbide, passage of a hydrocarbon through an electric arc, or partial combustion of methane. Decomposing it liberates heat; depending on degree of purity, it is also an explosive. An acetylene torch reaches about 6,000 °F (3,300 °C), hotter than combustion of any other known gas mixture. See alsohydrocarbon.