—acetylenic /euh set'l en"ik/, adj./euh set"l een', -in/, n. Chem.a colorless gas, C2H2, having an etherlike odor, produced usually by the action of water on calcium carbide or by pyrolysis of natural gas: used esp. in metal cutting and welding, as an illuminant, and in organic synthesis. Also called ethine, ethyne.[1860-65; ACETYL + -ENE]
* * *or ethyneSimplest alkyne, C2H2.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 also hydrocarbon.
* * *also called Ethyne,the simplest and best-known member of the hydrocarbon series containing one or more pairs of carbon atoms linked by triple bonds, called the acetylenic series, or alkynes. It is a colourless, inflammable gas widely used as a fuel in oxyacetylene welding and cutting of metals and as raw material in the synthesis of many organic chemicals and plastics; its chemical formula is C2H2.Pure acetylene is a colourless gas with a pleasant odour; as prepared from calcium carbide it usually contains traces of phosphine that cause an unpleasant garliclike odour. Acetylene can be decomposed to its elements with the liberation of heat. The decomposition may or may not give rise to explosion, depending on conditions. Pure acetylene under pressure in excess of about 15 pounds per square inch or in liquid or solid form explodes with extreme violence.Mixtures of air and acetylene are explosive over a wide range, from about 2.5 percent air in acetylene to about 12.5 percent acetylene in air. When burned with the correct amount of air, acetylene gives a pure, white light, and for this reason it was at one time used for illumination in locations where electric power was not available, e.g., buoys, miners' lamps, and road signals. The combustion of acetylene produces a large amount of heat, and, in a properly designed torch, the oxyacetylene flame attains the highest flame temperature (about 6,000° F, or 3,300° C) of any known mixture of combustible gases.The hydrogen atoms in acetylene can be replaced by metallic elements to form acetylides—e.g., acetylides of silver, copper, or sodium. The acetylides of silver, copper, mercury, and gold are detonated by heat, friction, or shock. In addition to its reactive hydrogen atom, the carbon–carbon triple bond can readily add halogens, halogen acids, hydrogen cyanide, alcohols, amines, and amides. Acetylene can also add to itself or to aldehydes and ketones. Many of the reactions mentioned here are used for the commercial manufacture of various industrial and consumer products, such as acetaldehyde, the synthetic rubber neoprene, water-base paints, vinyl fabric and floor coverings, dry-cleaning solvents, and aerosol insecticide sprays. Acetylene is produced by any of three methods: by reaction of water with calcium carbide, by passage of a hydrocarbon through an electric arc, or by partial combustion of methane with air or oxygen.
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ACÉTYLÈNE — L’acétylène, de formule brute C2H2, est le premier terme des alcynes ou hydrocarbures acétyléniques de formule générale Cn H2n 2. Ces derniers sont caractérisés par la présence d’une triple liaison (face=F0019 漣 C 令 C 漣) dans leur molécule.… … Encyclopédie Universelle
Acetylene — Acétylène Acétylène Structure tridimensionnelle de l acétylène Général Nom IUPAC éthyne … Wikipédia en Français
Acétylène — Structure tridimensionnelle de l acétylène Général Nom IUPAC éthyne … Wikipédia en Français
acetylene — (n.) gaseous hydrocarbon, 1864, from Fr. acétylène, coined by French chemist Marcelin Pierre Eugène Berthelot (1823 1907) from chemical ending ENE (Cf. ene) + acetyl, which was coined from acetic in 1839 by German chemist Justus von Liebig; see… … Etymology dictionary
Acetylene — A*cet y*lene, n. (Chem.) A gaseous compound of carbon and hydrogen, in the proportion of two atoms of the former to two of the latter. It is a colorless gas, with a peculiar, unpleasant odor, and is produced for use as an illuminating gas in a… … The Collaborative International Dictionary of English
Acetylēne — (Alkine), Kohlenwasserstoffe von der Formel CnH2n 2 mit dreifacher Bindung CH ≡ CH. vereinigen sich mit Wasserstoff im Entstehungsmoment zu Olefinen, die alsdann in Paraffine übergehen können. Sie werden durch konzentrierte Schwefelsäure… … Meyers Großes Konversations-Lexikon
Acetylene — Plural, frühere Bezeichnung für die Alkine … Universal-Lexikon
acetylene — ► NOUN ▪ a gas which burns with a bright flame, used in welding. ORIGIN from ACETIC ACID(Cf. ↑acetic acid) … English terms dictionary
acetylene — [ə set′ l ēn΄] n. [ ACETYL + ENE] a colorless, poisonous, highly flammable gaseous hydrocarbon, HC⋮CH, produced by the reaction of water and calcium carbide: used in organic compound synthesis, for lighting, and with oxygen in welding: the… … English World dictionary
Acetylene — HCCH redirects here. For other uses, see HCCH (disambiguation). Acetylene … Wikipedia