Back Etyn AF أسيتيلين Arabic Asetilen AZ استیلن AZB Ацэтылен BE Ацетилен Bulgarian ইথাইন Bengali/Bangla Acetilen BS Acetilè Catalan Ethyn Czech
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| Names | |
|---|---|
| Preferred IUPAC name | |
| Systematic IUPAC name
Ethyne[3] | |
| Identifiers | |
3D model (JSmol)
|
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| 906677 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.000.743 |
| EC Number |
|
| 210 | |
| KEGG | |
PubChem CID
|
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| RTECS number |
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| UNII | |
| UN number | 1001 (dissolved) 3138 (in mixture with ethylene and propylene) |
CompTox Dashboard (EPA)
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| Properties | |
| C2H2 | |
| Molar mass | 26.038 g·mol−1 |
| Appearance | Colorless gas |
| Odor | Odorless |
| Density | 1.1772 g/L = 1.1772 kg/m3 (0 °C, 101.3 kPa)[4] |
| Melting point | −80.8 °C (−113.4 °F; 192.3 K) Triple point at 1.27 atm |
| −84 °C; −119 °F; 189 K (1 atm) | |
| slightly soluble | |
| Solubility | slightly soluble in alcohol soluble in acetone, benzene |
| Vapor pressure | 44.2 atm (20 °C)[5] |
| Acidity (pKa) | 25[6] |
| Conjugate acid | Ethynium |
| −20.8×10−6 cm3/mol [7] | |
| Thermal conductivity | 21.4 mW·m−1·K−1 (300 K) [7] |
| Structure | |
| Linear | |
| Thermochemistry[7] | |
Heat capacity (C)
|
44.036 J·mol−1·K−1 |
Std molar
entropy (S⦵298) |
200.927 J·mol−1·K−1 |
Std enthalpy of
formation (ΔfH⦵298) |
227.400 kJ·mol−1 |
Gibbs free energy (ΔfG⦵)
|
209.879 kJ·mol−1 |
Std enthalpy of
combustion (ΔcH⦵298) |
1300 kJ·mol−1 |
| Hazards | |
| GHS labelling: | |
 
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| Danger | |
| H220, H336 | |
| P202, P210, P233, P261, P271, P304, P312, P340, P377, P381, P403, P405, P501 | |
| NFPA 704 (fire diamond) | |
| 300 °C (572 °F; 573 K) | |
| Explosive limits | 2.5–100% |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
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none[5] |
REL (Recommended)
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C 2500 ppm (2662 mg/m3)[5] |
IDLH (Immediate danger)
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N.D.[5] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Acetylene (systematic name: ethyne) is the chemical compound with the formula C2H2 and structure H−C≡C−H. It is a hydrocarbon and the simplest alkyne.[8] This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure form and thus is usually handled as a solution.[9] Pure acetylene is odorless, but commercial grades usually have a marked odor due to impurities such as divinyl sulfide and phosphine.[9][10]
As an alkyne, acetylene is unsaturated because its two carbon atoms are bonded together in a triple bond. The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of 180°.[11]
- ^ Favre, Henri A.; Powell, Warren H. (2014). Nomenclature of Organic Chemistry. IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. p. 375. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
The name acetylene is retained for the compound HC≡CH. It is the preferred IUPAC name, but substitution of any kind is not allowed; however, in general nomenclature, substitution is allowed, for example fluoroacetylene [fluoroethyne (PIN)], but not by alkyl groups or any other group that extends the carbon chain, nor by characteristic groups expressed by suffixes.
- ^ Moss, G.P. (web version). "P-14.3 Locants". Nomenclature of Organic Chemistry. IUPAC Recommendations and Preferred Names 2013. London: Queen Mary University. Section P-14.3.4.2 (d). Retrieved 24 August 2024.
- ^ Acyclic Hydrocarbons. Rule A-3. Unsaturated Compounds and Univalent Radicals Archived 10 October 2000 at the Wayback Machine, IUPAC Nomenclature of Organic Chemistry
- ^ Record of Acetylene in the GESTIS Substance Database of the Institute for Occupational Safety and Health
- ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0008". National Institute for Occupational Safety and Health (NIOSH).
- ^ "Acetylene – Gas Encyclopedia Air Liquide". Air Liquide. Archived from the original on 4 May 2022. Retrieved 27 September 2018.
- ^ a b c William M. Haynes; David R. Lide; Thomas J. Bruno (2016). CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data (2016-2017, 97th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4987-5428-6. OCLC 930681942. Archived from the original on 4 May 2022. Retrieved 4 May 2022.
- ^ R. H. Petrucci; W. S. Harwood; F. G. Herring (2002). General Chemistry (8th ed.). Prentice-Hall. p. 1072.
- ^ a b Pässler, Peter; Hefner, Werner; Buckl, Klaus; Meinass, Helmut; Meiswinkel, Andreas; Wernicke, Hans-Jürgen; Ebersberg, Günter; Müller, Richard; Bässler, Jürgen; Behringer, Hartmut; Mayer, Dieter (2008). "Acetylene Chemistry". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_097.pub3. ISBN 978-3527306732.
- ^ Compressed Gas Association (1995) Material Safety and Data Sheet – Acetylene Archived 11 July 2012 at the Wayback Machine
- ^ Whitten K. W., Gailey K. D. and Davis R. E. General Chemistry (4th ed., Saunders College Publishing 1992), pp. 328–329, 1046. ISBN 0-03-072373-6.