Ethylene oxide

Formula: C₂H₄O
Molecular weight: 44.0526
IUPAC Standard InChI: InChI=1S/C2H4O/c1-2-3-1/h1-2H2
IUPAC Standard InChIKey: IAYPIBMASNFSPL-UHFFFAOYSA-N
CAS Registry Number: 75-21-8
Chemical structure:
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Other names: Oxirane; Dihydrooxirene; Dimethylene oxide; Epoxyethane; Ethene oxide; ETO; Oxacyclopropane; Oxane; Oxidoethane; Oxirene, dihydro-; Oxyfume; Oxyfume 12; T-Gas; 1,2-Epoxyethane; Aethylenoxid; Amprolene; Anprolene; Anproline; ENT-26263; E.O.; 1,2-Epoxyaethan; Ethyleenoxide; Etylenu tlenek; FEMA No. 2433; Merpol; NCI-C50088; α,β-Oxidoethane; Oxiraan; Oxiran; Rcra waste number U115; Sterilizing gas ethylene oxide 100%; UN 1040; Qazi-ketcham
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Condensed phase thermochemistry data

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Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_liquid	-22.88 ± 0.30	kcal/mol	Ccb	Moureu and Dode, 1937	Reanalyzed by Cox and Pilcher, 1970, Original value = -22.8 kcal/mol; ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-301.85 ± 0.30	kcal/mol	Ccb	Moureu and Dode, 1937	Reanalyzed by Cox and Pilcher, 1970, Original value = -302.0 kcal/mol; Corresponding Δ_fHº_liquid = -22.88 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	35.719	cal/mol*K	N/A	Giauque and Gordon, 1949	DH

Constant pressure heat capacity of liquid

C_p,liquid (cal/mol*K)	Temperature (K)	Reference	Comment
20.77	285.	Giauque and Gordon, 1949	T = 15 to 283 K.; DH

References

Go To: Top, Condensed phase thermochemistry data, Notes

Moureu and Dode, 1937
Moureu, H.; Dode, M., Chaleurs de formation de l'oxyde d'ethylene, de l'ethanediol et de quelques homologues, Bull. Soc. Chim. France, 1937, 4, 637-647. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Giauque and Gordon, 1949
Giauque, W.F.; Gordon, J., The entropy of ethylene oxide. Heat capacity from 14 to 285K. Vapor pressure. Heats of fusion and vaporization, J. Am. Chem. Soc., 1949, 71, 2176-2181. [all data]

Notes

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Symbols used in this document:

C_p,liquid	Constant pressure heat capacity of liquid
S°_liquid	Entropy of liquid at standard conditions
Δ_cH°_liquid	Enthalpy of combustion of liquid at standard conditions
Δ_fH°_liquid	Enthalpy of formation of liquid at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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