Acetylene

Acetylene, also known as ethyne, is the simplest alkyne. It consists of two carbons triple bonded to each other and each one is single bonded to a hydrogen. It has the formula C2H2. Acetylene is very flammable and is used in welding torches (oxyacetylene torches use both oxygen and acetylene.) It is a colorless gas at room temperature. It sublimes at -84 Celsius, going directly from a solid to a gas.