Ethylene

Title: Ethylene
CAS Registry Number: 74-85-1
CAS Name: Ethene
Additional Names: elayl; olefiant gas
Molecular Formula: C2H4
Molecular Weight: 28.05
Percent Composition: C 85.64%, H 14.37%
Line Formula: CH2=CH2
Literature References: Plant hormone; occurs in ripening fruit, in illuminating gas (up to 4%). Prepd by decompn of petr gases or by dehydration of alcohol. Lab prepn from alc: Gattermann-Wieland, Praxis des Organischen Chemikers (de Gruyter, Berlin, 40th ed, 1961) p 98; F. A. Wunder, E. I. Leupold, Angew. Chem. Int. Ed. 19, 126 (1980). Biosynthesis from 1-aminocyclopropane-1-carboxylic acid: D. Adams, S. F. Yang, Proc. Natl. Acad. Sci. USA 76, 170 (1979). Proposed mechanism of biosynthesis: M. C. Pirrung, J. Am. Chem. Soc. 105, 7207 (1983). Toxicity data: Flury, Arch. Exp. Pathol. Pharmakol. 138, 65 (1928). Comprehensive monograph: S. A. Miller, Ethylene and its Industrial Derivatives (Ernest Benn Ltd., London, 1969) 1321 pp. Review of ethylene in biological systems: Spencer, Fortschr. Chem. Org. Naturst. 27, 31-80 (1969); of manuf: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 376-384; of carcinogenic risk: IARC Monographs 60, 45-71 (1994). Review: K. M. Sundaram et al., in Kirk-Othmer Encyclopedia of Chemical Technology vol. 9 (Wiley-Interscience, New York, 4th ed., 1994) pp 877-915.
Properties: Colorless, flammable gas with faint sweet odor. Burns with a luminous flame. Solidif -181° forming monoclinic prisms. mp -169.4°, bp700 -102.4°. Vapor density 0.978 (air = 1.00). One liter of ethylene gas at 760 mm and 0° weighs 1.260 g. bp2 atm -90.8°; bp10 atm -52.8°; bp30 atm -14.2°; bp50 atm 8.9°. d46.5 (liquid): 0.30342. Critical temp +9.6°; crit press. 50.7 atm. One volume of ethylene gas dissolves in about 4 vols of water at 0°, in about 9 vols of water at 25°, in 0.5 vol alcohol at 25°, in about 0.05 vol ether at 15.5°. Sol in acetone, benzene. Explosive limits (% vol in air), lower: 3.02; upper: 34. Autoignition temp: 1009°F (+543°C). LC for mice in air: 950,000 ppm (Flury).
Melting point: mp -169.4°
Boiling point: bp700 -102.4°; bp2 atm -90.8°; bp10 atm -52.8°; bp30 atm -14.2°; bp50 atm 8.9°
Density: d46.5 (liquid): 0.30342
Toxicity data: LC for mice in air: 950,000 ppm (Flury)
CAUTION: Can act as a simple asphyxiant due to oxygen displacement. Exposure to high concns may cause CNS depression, unconsciousness. See Patty's Industrial Hygiene and Toxicology vol. 2B, G. D. Clayton, F. E. Clayton, Eds. (John Wiley & Sons, New York, 4th ed., 1994) p 1241-1244.
Use: Oxyethylene welding and cutting metals; manuf alcohol, mustard gas, and many other organics. Manuf ethylene oxide (for plastics), "Polythene", polystyrene and other plastics. Plant growth regulator; used commercially to accelerate the ripening of various fruits.
Therap-Cat: Anesthetic (inhalation).
Therap-Cat-Vet: Has been used as inhalation anesthetic.
Keywords: Anesthetic (Inhalation).
Ethylene Bromohydrin Ethylene Chlorohydrin Ethylene Cyanohydrin Ethylene Dibromide Ethylene Dichloride

Ethylene
Ethylene-CRC-MW-dimensions-2D.png
Ethylene-CRC-MW-3D-balls.png Ethylene-3D-vdW.png
Identifiers
CAS number 74-85-1 YesY
PubChem 6325
ChemSpider 6085 YesY
UNII 91GW059KN7 YesY
EC-number 200-815-3
KEGG C06547 YesY
ChEBI CHEBI:18153 YesY
ChEMBL CHEMBL117822 YesY
Jmol-3D images Image 1
Properties
Molecular formula C
2
H
4
Molar mass 28.05 g/mol
Appearance colorless gas
Density 1.178 kg/m3 at 15 °C, gas[1]
Melting point −169.2 °C (104.0 K, -272.6 °F)
Boiling point −103.7 °C (169.5 K, -154.7 °F)
Solubility in water 3.5 mg/100 mL (17 °C)[citation needed] ; 2.9 mg/L[2]
Solubility in ethanol 4.22 mg/L[2]
Solubility in diethyl ether good[2]
Acidity (pKa) 44
Structure
Molecular shape D2h
Dipole moment zero
Thermochemistry
Std molar
entropy So298
219.32 J·K−1·mol−1
Std enthalpy of
formation ΔfHo298
+52.47 kJ/mol
Hazards
MSDS External MSDS
EU classification Extremely flammable (F+)
NFPA 704
NFPA 704.svg
4
1
2
Flash point −136 °C; −213 °F; 137 K
Autoignition temperature 542.8 °C; 1,009.0 °F; 815.9 K
Related compounds
Related compounds Ethane
Acetylene
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Ethylene (IUPAC name: ethene) is a hydrocarbon with the formula C
2
H
4
or H2C=CH2. It is a colorless flammable gas with a faint "sweet and musky" odor when pure.[3] It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds), and the simplest unsaturated hydrocarbon after acetylene (C
2
H
2
).

Ethylene is widely used in chemical industry, and its worldwide production (over 109 million tonnes in 2006) exceeds that of any other organic compound.[4][5] Ethylene is also an important natural plant hormone, used in agriculture to force the ripening of fruits.[6]