Acetic acid

• Formula: C₂H₄O₂
• Molecular weight: 60.0520
• IUPAC Standard InChI: InChI=1S/C2H4O2/c1-2(3)4/h1H3,(H,3,4) Copy

  
• IUPAC Standard InChIKey: QTBSBXVTEAMEQO-UHFFFAOYSA-N Copy
• CAS Registry Number: 64-19-7
• Chemical structure:
  This structure is also available as a 2d Mol file or as a computed 3d SD file
  The 3d structure may be viewed using Java or Javascript.
• Isotopologues:
  • Acetic acid-d4
• Other names: Ethanoic acid; Ethylic acid; Glacial acetic acid; Methanecarboxylic acid; Vinegar acid; CH3COOH; Acetasol; Acide acetique; Acido acetico; Azijnzuur; Essigsaeure; Octowy kwas; Acetic acid, glacial; Kyselina octova; UN 2789; Aci-jel; Shotgun; Ethanoic acid monomer; NSC 132953
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Phase change data
  • Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 79
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Vibrational and/or electronic energy levels
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
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Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Gas phase ion energetics data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Constant pressure heat capacity of gas

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

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

Constant pressure heat capacity of liquid

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LL - Sharon G. Lias and Joel F. Liebman

View reactions leading to C₂H₄O₂⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

 +  =

By formula: C₂H₃O₂^- + H⁺ = C₂H₄O₂

C₂H₃O₂^- +  =

By formula: C₂H₃O₂^- + H⁺ = C₂H₄O₂

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Weltner W., 1955
Weltner W., Jr., The vibrational spectrum, associative and thermodynamic properties of acetic acid vapor, J. Am. Chem. Soc., 1955, 77, 3941-3950. [all data]

Chao J., 1986
Chao J., Thermodynamic properties of key organic oxygen compounds in the carbon range C1 to C4. Part 2. Ideal gas properties, J. Phys. Chem. Ref. Data, 1986, 15, 1369-1436. [all data]

Halford J.O., 1941
Halford J.O., The entropy of acetic acid, J. Chem. Phys., 1941, 9, 859-863. [all data]

Chao J., 1978
Chao J., Ideal gas thermodynamic properties of methanoic and ethanoic acids, J. Phys. Chem. Ref. Data, 1978, 7, 363-377. [all data]

Steele, Chirico, et al., 1997
Steele, W.V.; Chirico, R.D.; Cowell, A.B.; Knipmeyer, S.E.; Nguyen, A., Thermodynamic properties and ideal-gas enthalpies of formation for 2-aminoisobutyric acid (2-methylalanine), acetic acid, (4-methyl-3-penten-2-one), 4-methylpent-1-ene, 2,2'-bis(phenylthio)propane, and glycidyl phenyl ether (1,2-epoxy-3-phenoxypropane), J. Chem. Eng. Data, 1997, 42, 1052-1066. [all data]

Lebedeva, 1964
Lebedeva, N.D., Heats of combustion of monocarboxylic acids, Russ. J. Phys. Chem. (Engl. Transl.), 1964, 38, 1435-1437. [all data]

Evans and Skinner, 1959
Evans, F.W.; Skinner, H.A., The heat of combustion of acetic acid, Trans. Faraday Soc., 1959, 55, 260-261. [all data]

Carson and Skinner, 1949
Carson, A.S.; Skinner, H.A., 201. Carbon-halogen bond energies in the acetyl halides, J. Chem. Soc., 1949, 936-939. [all data]

Schjanberg, 1935
Schjanberg, E., Die Verbrennungswarmen und die Refraktionsdaten einiger chlorsubstituierter Fettsauren und Ester., Z. Phys. Chem. Abt. A, 1935, 172, 197-233. [all data]

Martin and Andon, 1982
Martin, J.F.; Andon, R.J.L., Thermodynamic properties of organic oxygen compounds. Part LII. Molar heat capacity of ethanoic, propanoic, and butanoic acids, J. Chem. Thermodynam., 1982, 14, 679-688. [all data]

Parks and Kelley, 1925
Parks, G.S.; Kelley, K.K., Thermal data on organic compounds. II. The heat capacities of five organic compounds. The entropies and free energies of some homologous series of aliphatic compounds, J. Am. Chem. Soc., 1925, 47, 2089-2097. [all data]

Swietoslawski and Zielenkiewicz, 1958
Swietoslawski, W.; Zielenkiewicz, A., Mean specific heat of some ternary azeotropes, Bull. Acad. Pol. Sci. Ser. Sci. Chim., 1958, 6, 365-366. [all data]

Radulescu and Jula, 1934
Radulescu, D.; Jula, O., Beiträge zur Bestimmung der Abstufung der Polarität des Aminstickstoffes in den organischen Verbindungen, Z. Phys. Chem., 1934, B26, 390-393. [all data]

Neumann, 1932
Neumann, M.B., Die Untersuchung der Wärmekapazität vom binären System CH₃COOH + H₂O bei verschiedenen Temperaturen, Z. Phys. Chem., 1932, A158, 258-264. [all data]

Parks, Kelley, et al., 1929
Parks, G.S.; Kelley, K.K.; Huffman, H.M., Thermal data on organic compounds. V. A revision of the entropies and free energies of nineteen organic compounds, J. Am. Chem. Soc., 1929, 51, 1969-1973. [all data]

Pickering, 1895
Pickering, S.U., A comparison of some properties of acetic acid and its chloro- and bromo-derivatives, J. Chem. Soc., 1895, 67, 664-684. [all data]

von Reis, 1881
von Reis, M.A., Die specifische Wärme flüssiger organischer Verbindungen und ihre Beziehung zu deren Moleculargewicht, Ann. Physik [3], 1881, 13, 447-464. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Traeger, McLouglin, et al., 1982
Traeger, J.C.; McLouglin, R.G.; Nicholson, A.J.C., Heat of formation for acetyl cation in the gas phase, J. Am. Chem. Soc., 1982, 104, 5318. [all data]

Holmes, Fingas, et al., 1981
Holmes, J.L.; Fingas, M.; Lossing, F.P., Towards a general scheme for estimating the heats of formation of organic ions in the gas phase. Part I. Odd-electron cations, Can. J. Chem., 1981, 59, 80. [all data]

Holmes and Lossing, 1980
Holmes, J.L.; Lossing, F.P., Thermochemistry and unimolecular reactions of ionized acetic acid and its enol in the gas phase., J. Am. Chem. Soc., 1980, 102, 3732. [all data]

Holmes and Lossing, 1980, 2
Holmes, J.L.; Lossing, F.P., Gas-phase heats of formation of keto and enol ions of carbonyl compounds., J. Am. Chem. Soc., 1980, 102, 1591. [all data]

Akopyan and Villem, 1976
Akopyan, M.E.; Villem, Ya.Ya., Ion-molecule reactions in the photoionization of formic and acetic acid vapors, High Energy Chem., 1976, 10, 24. [all data]

Watanabe, Yokoyama, et al., 1974
Watanabe, I.; Yokoyama, Y.; Ikeda, S., Vibrational structures in the He(I) photoelectron spectra of carboxylic acids, Bull. Chem. Soc. Jpn., 1974, 47, 627. [all data]

Knowles and Nicholson, 1974
Knowles, D.J.; Nicholson, A.J.C., Ionization energies of formic and acetic acid monomers, J. Chem. Phys., 1974, 60, 1180. [all data]

Watanabe, Yokoyama, et al., 1973
Watanabe, I.; Yokoyama, Y.; Ikeda, S., Lone pair ionization potentials of carboxylic acids determined by He(I) photoelectron spectroscopy, Bull. Chem. Soc. Jpn., 1973, 46, 1959. [all data]

Thomas, 1972
Thomas, R.K., Photoelectron spectroscopy of hydrogen-bonded systems: spectra of monomers, dimers and mixed complexes of carboxylic acides, Proc. R. Soc. London A:, 1972, 331, 249. [all data]

Sweigart and Turner, 1972
Sweigart, D.A.; Turner, D.W., Lone pair orbitals and their interactions studied by photoelectron spectroscopy. I. Carboxylic acids and their derivatives, J. Am. Chem. Soc., 1972, 94, 5592. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Vilesov, 1960
Vilesov, F.I., The photoionization of vapors of compounds whose molecules contain carbonyl groups, Dokl. Phys. Chem., 1960, 132, 521, In original 1332. [all data]

Watanabe, 1957
Watanabe, K., Ionization potentials of some molecules, J. Chem. Phys., 1957, 26, 542. [all data]

Von Niessen, Bieri, et al., 1980
Von Niessen, W.; Bieri, G.; Asbrink, L., 30.4 nm He(II) photoelectron spectra of organic molecules. Part III. Oxo-compounds (C,H,O), J. Electron Spectrosc. Relat. Phenom., 1980, 21, 175. [all data]

Carnovale, Gan, et al., 1980
Carnovale, F.; Gan, T.H.; Peel, J.B., Photoelectron spectroscopic studies of the monomers and dimers of acetic and trifluoracetic acids, J. Electron Spectrosc. Relat. Phenom., 1980, 20, 53. [all data]

Benoit and Harrison, 1977
Benoit, F.M.; Harrison, A.G., Predictive value of proton affinity. Ionization energy correlations involving oxygenated molecules, J. Am. Chem. Soc., 1977, 99, 3980. [all data]

Rao, 1975
Rao, C.N.R., Lone-pair ionization bands of chromophores in the photoelectron spectra of organic molecules, Indian J. Chem., 1975, 13, 950. [all data]

Kimura, Katsumata, et al., 1975
Kimura, K.; Katsumata, S.; Yamazaki, T.; Wakabayashi, H., UV photoelectron spectra and sum rule consideration; out-of-plane orbitals of unsaturated compounds with planar-skeleton structure, J. Electron Spectrosc. Relat. Phenom., 1975, 6, 41. [all data]

Green and Hayes, 1975
Green, J.C.; Hayes, A.J., Ionization energies of an Mo-Mo quadruple bond; a He(I) photoelectron study of some molybdenum-dycarboxylate dimers, Chem. Phys. Lett., 1975, 31, 306. [all data]

Stepanov, Perov, et al., 1988
Stepanov, A.N.; Perov, A.A.; Kabanov, S.P.; Simonov, A.P., Formation of long-lived, highly excited atoms during dissociative excitation of CH₃CN, CH₃CH₂OH, CH₃COOH, HCOOH, and C₄H₄S molecules on electron impact, Russ. J. Phys. Chem., 1988, 22, 81. [all data]

Haney and Franklin, 1969
Haney, M.A.; Franklin, J.L., Excess energies in mass spectra of some oxygen-containing organic compounds, J. Chem. Soc. Faraday Trans., 1969, 65, 1794. [all data]

Shigorin, Filyugina, et al., 1966
Shigorin, D.N.; Filyugina, A.D.; Potapov, V.K., Ionization and dissociation of molecules of acetaldehyde, acetone, and acetic acid on electron impact, Teor. i Eksperim. Khim., 1966, 2, 554, In original 417. [all data]

Selim and Helal, 1981
Selim, E.T.M.; Helal, A.I., Heat of formation of CH₂=OH⁺ fragment ion, Indian J. Pure Appl. Phys., 1981, 19, 977. [all data]

Majer, Patrick, et al., 1961
Majer, J.R.; Patrick, C.R.; Robb, J.C., Appearance potentials of the acetyl radical-ion, J. Chem. Soc. Faraday Trans., 1961, 57, 14. [all data]

Angel and Ervin, 2006
Angel, L.A.; Ervin, K.M., Gas-phase acidities and O-H bond dissociation enthalpies of phenol, 3-methylphenol, 2,4,6-trimethylphenol, and ethanoic acid, J. Phys. Chem. A, 2006, 110, 35, 10392-10403, https://doi.org/10.1021/jp0627426 . [all data]

Taft and Topsom, 1987
Taft, R.W.; Topsom, R.D., The Nature and Analysis of Substituent Effects, Prog. Phys. Org. Chem., 1987, 16, 1. [all data]

Cumming and Kebarle, 1978
Cumming, J.B.; Kebarle, P., Summary of gas phase measurements involving acids AH. Entropy changes in proton transfer reactions involving negative ions. Bond dissociation energies D(A-H) and electron affinities EA(A), Can. J. Chem., 1978, 56, 1. [all data]

Fujio, McIver, et al., 1981
Fujio, M.; McIver, R.T., Jr.; Taft, R.W., Effects on the acidities of phenols from specific substituent-solvent interactions. Inherent substituent parameters from gas phase acidities, J. Am. Chem. Soc., 1981, 103, 4017. [all data]

Muftakhov, Vasil'ev, et al., 1999
Muftakhov, M.V.; Vasil'ev, Y.V.; Mazunov, V.A., Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry, Rapid Commun. Mass Spectrom., 1999, 13, 12, 1104-1108, https://doi.org/10.1002/(SICI)1097-0231(19990630)13:12<1104::AID-RCM619>3.0.CO;2-C . [all data]

Grabowski and Cheng, 1989
Grabowski, J.J.; Cheng, X., Gas-Phase Formation of the Enolate Monoanion of Acetic Acid by Proton Abstraction, J. Am. Chem. Soc., 1989, 111, 8, 3106, https://doi.org/10.1021/ja00190a078 . [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Gas phase ion energetics data, References

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,gas	Constant pressure heat capacity of gas
  Cp,liquid	Constant pressure heat capacity of liquid
  IE (evaluated)	Recommended ionization energy
  S°gas	Entropy of gas at standard conditions
  S°liquid	Entropy of liquid at standard conditions
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions

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