Ethyne

Ethyne, also known as acetylene, is the simplest hydrocarbon of the alkyne family, with the formula C2H2. It is a colorless gas at room temperature and pressure. The molecule is linear, represented as H-C≡C-H, with carbon atoms sp hybridized. The C≡C triple bond is about 1.20 angstroms long, and the C–H bonds are about 1.06 angstroms. The molecule has a linear geometry with a bond angle of 180 degrees and is moderately soluble in water.

Industrial production and storage methods rely on stabilizing the gas. Ethyne is chiefly produced by the hydrolysis of calcium carbide: CaC2 + H2O → Ca(OH)2 + C2H2. In industry, acetylene is often dissolved in acetone or dimethylformamide inside a porous filler in steel cylinders to prevent dangerous decomposition under pressure. Pure acetylene is highly flammable and can form explosive mixtures with air or oxidizers; storage and handling require strict safety measures. It can form explosive copper acetylide with copper and copper alloys, so contact with copper components is avoided.

Reactions and applications: Ethyne participates in many addition reactions characteristic of alkynes and serves as a versatile building block in organic synthesis. It is a feedstock for the production of chemicals such as vinyl chloride and other polymers and can be polymerized to polyacetylene under certain conditions, a conducting polymer studied in materials science. In metalworking, acetylene is widely used in oxy-acetylene flame systems, where flame temperatures can reach about 3,500 °C, enabling welding and cutting.

---