Oxalic acid
- Formula: C2H2O4
- Molecular weight: 90.0349
- IUPAC Standard InChIKey: MUBZPKHOEPUJKR-UHFFFAOYSA-N
- CAS Registry Number: 144-62-7
- 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. - Other names: Ethanedioic acid; Aktisal; Aquisal; Oxiric acid; HOOCCOOH; Acide oxalique; Acido ossalico; Ethanedionic acid; Kyselina stavelova; NCI-C55209; Oxaalzuur; Oxalsaeure; Ethane-1,2-dioic acid; NSC 62774
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Gas phase thermochemistry data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Glushko Thermocenter, Russian Academy of Sciences, Moscow
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
9.178 | 50. | Dorofeeva O.V., 1997 | p=1 bar. |
10.76 | 100. | ||
12.98 | 150. | ||
15.56 | 200. | ||
20. ± 1. | 298.15 | ||
20.44 | 300. | ||
24.419 | 400. | ||
27.545 | 500. | ||
29.988 | 600. | ||
31.917 | 700. | ||
33.470 | 800. | ||
34.742 | 900. | ||
35.801 | 1000. | ||
36.695 | 1100. | ||
37.455 | 1200. | ||
38.107 | 1300. | ||
38.671 | 1400. | ||
39.159 | 1500. |
Condensed phase thermochemistry data
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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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°solid | -198.12 ± 0.11 | kcal/mol | Cm | Brown, 1969 | ALS |
ΔfH°solid | -198.36 ± 0.23 | kcal/mol | Ccb | Wilhoit and Shiao, 1964 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°solid | -58.06 ± 0.22 | kcal/mol | Ccb | Wilhoit and Shiao, 1964 | Corresponding ΔfHºsolid = -198.36 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°solid | -60.59 ± 0.11 | kcal/mol | Ccb | Verkade, Hartman, et al., 1926 | Reanalyzed by Cox and Pilcher, 1970, Original value = -60.1 kcal/mol; See Verkade, Hartman, et al., 1924; Corresponding ΔfHºsolid = -195.83 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°solid,1 bar | 27.63 | cal/mol*K | N/A | Luff and Reed, 1982 | DH |
Constant pressure heat capacity of solid
Cp,solid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
25.31 | 298.15 | Luff and Reed, 1982 | T = 5 to 320 K.; DH |
34.9 | 340. | David, 1964 | T = 298 to 373 K. Mean value. T = uncertain.; DH |
28.20 | 323. | Satoh and Sogabe, 1939 | T = 0 to 100°C. Mean value given.; DH |
28.70 | 298.1 | Parks, Kelley, et al., 1929 | Extrapolation below 90 K, 38.49 J/mol*K. Revision of previous data.; DH |
Phase change data
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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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tfus | 464.45 | K | N/A | Wilhoit and Shiao, 1964, 2 | Uncertainty assigned by TRC = 1.5 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔsubH° | 23.400 | kcal/mol | V | Bradley and Cleasby, 1953 | ALS |
Enthalpy of sublimation
ΔsubH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
14.8 | 306. | A | Granovskaya, 1947 | Based on data from 292. to 320. K.; AC |
21.7 | 333. to 378. | GS | Noyes and Wobbe, 1926 | AC |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
0.3107 | 393.2 | crystaline, II | crystaline, I | Petropavlov, Tsygankova, et al., 1988 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
0.79 | 393.2 | crystaline, II | crystaline, I | Petropavlov, Tsygankova, et al., 1988 | DH |
Reaction thermochemistry data
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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:
B - John E. Bartmess
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.
Individual Reactions
C2HO4- + =
By formula: C2HO4- + H+ = C2H2O4
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 324.2 ± 2.0 | kcal/mol | CIDC | Kumar, Prabhakar, et al., 2005 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 316.3 ± 2.0 | kcal/mol | CIDC | Kumar, Prabhakar, et al., 2005 | gas phase; B |
By formula: C4H6O4 + 2H2O = C2H2O4 + 2CH4O
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 4.165 ± 0.016 | kcal/mol | Cm | Anthoney, Finch, et al., 1975 | solid phase; solvent: Water; Hydrolysis; ALS |
Henry's Law data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Rolf Sander
Henry's Law constant (water solution)
kH(T) = k°H exp(d(ln(kH))/d(1/T) ((1/T) - 1/(298.15 K)))
k°H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(kH))/d(1/T) = Temperature dependence constant (K)
k°H (mol/(kg*bar)) | d(ln(kH))/d(1/T) (K) | Method | Reference | Comment |
---|---|---|---|---|
5.0×10+8 | E | N/A | Value obtained by missing citation using the group contribution method. | |
7.0×10+6 | X | N/A | Value given here as quoted by missing citation. |
Gas phase ion energetics data
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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:
B - John E. Bartmess
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
LL - Sharon G. Lias and Joel F. Liebman
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
11.20 | PE | McGlynn and Meeks, 1976 | Vertical value; LLK |
11.20 | PE | Meeks, Arnett, et al., 1975 | Vertical value; LLK |
11.20 | PE | Arnett, Newkome, et al., 1974 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C2O2+ | 17.4 ± 0.1 | H2O+O | EI | Chen and Holmes, 1994 | LL |
De-protonation reactions
C2HO4- + =
By formula: C2HO4- + H+ = C2H2O4
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 324.2 ± 2.0 | kcal/mol | CIDC | Kumar, Prabhakar, et al., 2005 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 316.3 ± 2.0 | kcal/mol | CIDC | Kumar, Prabhakar, et al., 2005 | gas phase; B |
Mass spectrum (electron ionization)
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
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Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | Japan AIST/NIMC Database- Spectrum MS-NW-1856 |
NIST MS number | 229396 |
UV/Visible spectrum
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Spectrum
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Additional Data
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Source | Pestemer and Alslev-Klinker, 1949 |
---|---|
Owner | INEP CP RAS, NIST OSRD Collection (C) 2007 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
Origin | INSTITUTE OF ENERGY PROBLEMS OF CHEMICAL PHYSICS, RAS |
Source reference | RAS UV No. 9249 |
Instrument | Quartz spectrograph |
Melting point | 189.5 dec |
Boiling point | sub 157 |
Gas Chromatography
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Normal alkane RI, non-polar column, temperature ramp
Column type | Active phase | I | Reference | Comment |
---|---|---|---|---|
Capillary | RTX-5 | 748. | Setkova, Risticevic, et al., 2007 | 10. m/0.18 mm/0.2 μm, He, 40. C @ 0.5 min, 50. K/min, 275. C @ 0.5 min |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, NIST Free Links, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Dorofeeva O.V., 1997
Dorofeeva O.V.,
Unpublished results. Thermocenter of Russian Academy of Science, Moscow, 1997. [all data]
Brown, 1969
Brown, M.A.H.,
The heats of formation of selected cyanide and oxalate compounds,
Diss. Abstr., 1969, 29, 3696. [all data]
Wilhoit and Shiao, 1964
Wilhoit, R.C.; Shiao, D.,
Thermochemistry of biologically important compounds. Heats of combustion of solid organic acids.,
J. Chem. Eng. Data, 1964, 9, 595-599. [all data]
Verkade, Hartman, et al., 1926
Verkade, P.E.; Hartman, H.; Coops, J.,
Calorimetric researches. X. Heats of combustion of successive terms of homologous series: dicarboxylic acids of the oxalic acid series,
Rec. Trav. Chim. Pays/Bas, 1926, 45, 373-393. [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]
Verkade, Hartman, et al., 1924
Verkade, P.E.; Hartman, H.; Coops, J., Jr.,
Chemistry - The molecular heat of combustion of successive terms of homologous series,
Kom. Med. Akad. Ueknschap. Proc., 1924, 27, 859-866. [all data]
Luff and Reed, 1982
Luff, B.B.; Reed, R.B.,
Low-temperature heat capacity and entropy of oxalic acid and of biuret,
J. Chem. Eng. Data, 1982, 27, 290-292. [all data]
David, 1964
David, D.J.,
Determination of specific heat and heat of fusion by differential thermal analysis. Study of theory and operating parameters,
Anal. Chem., 1964, 36, 2162-2166. [all data]
Satoh and Sogabe, 1939
Satoh, S.; Sogabe, T.,
The specific heats of some solid aliphatic acids and their ammonium salts and the atomic heat of nitrogen,
Sci. Pap. Inst. Phys. Chem. Res. (Tokyo), 1939, 36, 97-105. [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]
Wilhoit and Shiao, 1964, 2
Wilhoit, R.C.; Shiao, D.,
Thermochemistry of Biologically Important Compounds. Heats of Combustion of Solid Organic Acids,
J. Chem. Eng. Data, 1964, 9, 595. [all data]
Bradley and Cleasby, 1953
Bradley, R.S.; Cleasby, T.G.,
The vapour pressure and lattice energy of hydrogen-bonded crystals. Part I. Oxamide, oxamic acid, and rubeanie acid,
J. Chem. Soc., 1953, 1681-16. [all data]
Granovskaya, 1947
Granovskaya, A.,
Russ. J. Phys. Chem., 1947, 21, 967. [all data]
Noyes and Wobbe, 1926
Noyes, W. Albert; Wobbe, Delbert E.,
THE VAPOR PRESSURE OF ANHYDROUS OXALIC ACID,
J. Am. Chem. Soc., 1926, 48, 7, 1882-1887, https://doi.org/10.1021/ja01418a012
. [all data]
Petropavlov, Tsygankova, et al., 1988
Petropavlov, N.N.; Tsygankova, I.G.; Teslenko, L.A.,
Microcalorimetric investigation of polymorphic transitions in organic crystals,
Sov. Phys. Crystallogr., 1988, 33(6), 853-855. [all data]
Kumar, Prabhakar, et al., 2005
Kumar, M.R.; Prabhakar, S.; Nagaveni, V.; Vairamani, M.,
Estimation of gas-phase acidities of a series of dicarboxylic acids by the kinetic method,
Rapid Commun. Mass Spectrom., 2005, 19, 8, 1053-1057, https://doi.org/10.1002/rcm.1888
. [all data]
Anthoney, Finch, et al., 1975
Anthoney, M.E.; Finch, A.; Stephens, M.,
The solution of dimethyl oxalate and oxalic acid in water and alkali. Standard enthalpy of formation of dimethyl oxalate,
Thermochim. Acta, 1975, 12, 427-431. [all data]
McGlynn and Meeks, 1976
McGlynn, S.P.; Meeks, J.L.,
Photoelectron spectra of carbonyls, carbonates, oxalates and esterification effects,
J. Electron Spectrosc. Relat. Phenom., 1976, 8, 85. [all data]
Meeks, Arnett, et al., 1975
Meeks, J.L.; Arnett, J.F.; Larson, D.B.; McGlynn, S.P.,
Photoelectron spectroscopy of carbonyls. Urea, oxamide, oxalic acid and oxamic acid,
J. Am. Chem. Soc., 1975, 97, 3905. [all data]
Arnett, Newkome, et al., 1974
Arnett, J.F.; Newkome, G.; Mattice, W.L.; McGlynn, S.P.,
Excited electronic states of the α-dicarbonyls,
J. Am. Chem. Soc., 1974, 96, 4385. [all data]
Chen and Holmes, 1994
Chen, H.; Holmes, J.L.,
The generation of OC2O+ and OC2O and a study of ionized OC3O and C2O by tandem mass spectrometry,
Int. J. Mass Spectrom. Ion Processes, 1994, 133, 111. [all data]
Pestemer and Alslev-Klinker, 1949
Pestemer, M.; Alslev-Klinker, A.,
Z. Elektrochem, 1949, 53, 387. [all data]
Setkova, Risticevic, et al., 2007
Setkova, L.; Risticevic, S.; Pawliszyn, J.,
Rapid headspace solid-phase microextraction-gas chromatographic?time-of-flight mass spectrometric method for qualitative profiling of ice wine volatile fraction II: Classification of Canadian and Czech ice wines using statistical evaluation of the data,
J. Chromatogr. A, 2007, 1147, 2, 224-240, https://doi.org/10.1016/j.chroma.2007.02.052
. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, Mass spectrum (electron ionization), UV/Visible spectrum, Gas Chromatography, NIST Free Links, References
- Symbols used in this document:
AE Appearance energy Cp,gas Constant pressure heat capacity of gas Cp,solid Constant pressure heat capacity of solid S°solid,1 bar Entropy of solid at standard conditions (1 bar) Tfus Fusion (melting) point d(ln(kH))/d(1/T) Temperature dependence parameter for Henry's Law constant k°H Henry's Law constant at 298.15K ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition ΔcH°solid Enthalpy of combustion of solid at standard conditions ΔfH°solid Enthalpy of formation of solid at standard conditions ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔsubH Enthalpy of sublimation ΔsubH° Enthalpy of sublimation at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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