Selected ATcT [1, 2] enthalpy of formation based on version 1.156 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.148 to include species relevant to a recent study of the oxidation of ethylene [4] as well as new measurements that led to refining the thermochemistry of CF and SiF and their cations [5].

Oxalic acid

Formula: (C(O)OH)2 (cr)

CAS RN: 144-62-7

ATcT ID: 144-62-7*500

SMILES: C(=O)(C(=O)O)O

SMILES: OC(=O)C(=O)O

InChI: InChI=1S/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)

InChIKey: MUBZPKHOEPUJKR-UHFFFAOYSA-N

Hills Formula: C2H2O4

2D Image:

Aliases: (C(O)OH)2; Oxalic acid; Ethanedionic acid; (COOH)2; HOC(O)C(O)OH; HOOCCOOH; HO(c=O)2OH; HO(CO)2OH

Relative Molecular Mass: 90.0349 ± 0.0020

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
-819.55	-829.64	± 0.42	kJ/mol

Top contributors to the provenance of Δ_fH° of (C(O)OH)2 (cr)

The 2 contributors listed below account for 96.6% of the provenance of Δ_fH° of (C(O)OH)2 (cr).

Please note: The list is limited to 20 most important contributors or, if less, a number sufficient to account for 90% of the provenance. The Reference acts as a further link to the relevant references and notes for the measurement. The Measured Quantity is normaly given in the original units; in cases where we have reinterpreted the original measurement, the listed value may differ from that given by the authors. The quoted uncertainty is the a priori uncertainty used as input when constructing the initial Thermochemical Network, and corresponds either to the value proposed by the original authors or to our estimate; if an additional multiplier is given in parentheses immediately after the prior uncertainty, it corresponds to the factor by which the prior uncertainty needed to be multiplied during the ATcT analysis in order to make that particular measurement consistent with the prevailing knowledge contained in the Thermochemical Network.

Contribution (%)	TN ID	Reaction	Measured Quantity	Reference
78.6	5298.2	(C(O)OH)2 (cr) + 1/2 O2 (g) → 2 CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -58.13 ± 0.11 kcal/mol	Brown 1968
17.9	5298.1	(C(O)OH)2 (cr) + 1/2 O2 (g) → 2 CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -58.06 ± 0.23 kcal/mol	Wilhoit 1964

Top 10 species with enthalpies of formation correlated to the Δ_fH° of (C(O)OH)2 (cr)

Please note: The correlation coefficients are obtained by renormalizing the off-diagonal elements of the covariance matrix by the corresponding variances.
The correlation coefficient is a number from -1 to 1, with 1 representing perfectly correlated species, -1 representing perfectly anti-correlated species, and 0 representing perfectly uncorrelated species.

Correlation Coefficent (%)	Species Name	Formula	Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
11.2	Oxalic acid	(C(O)OH)2 (g)	-721.0	-731.6	± 1.2	kJ/mol	90.0349 ± 0.0020	144-62-7*0
7.3	Carbonic acid	C(O)(OH)2 (aq, undissoc)		-698.670	± 0.028	kJ/mol	62.0248 ± 0.0012	463-79-6*1000
6.4	Carbon dioxide	CO2 (g)	-393.111	-393.477	± 0.015	kJ/mol	44.00950 ± 0.00100	124-38-9*0
6.3	Carbon dioxide cation	[CO2]+ (g)	936.090	936.924	± 0.017	kJ/mol	44.00895 ± 0.00100	12181-61-2*0
5.9	Benzoic acid	C6H5C(O)OH (cr,l)	-367.33	-384.74	± 0.17	kJ/mol	122.1213 ± 0.0056	65-85-0*500
5.9	Succinic acid	(CH2C(O)OH)2 (cr,l)	-918.49	-940.22	± 0.12	kJ/mol	118.0880 ± 0.0034	110-15-6*500
5.5	Hydroxyformyl	HOCO (g, trans)	-181.15	-184.12	± 0.40	kJ/mol	45.0174 ± 0.0010	2564-86-5*1
5.5	Hydroxyformyl	HOCO (g)	-181.15	-183.70	± 0.40	kJ/mol	45.0174 ± 0.0010	2564-86-5*0
5.1	Hydrogen carbonate	[HOC(O)O]- (aq)		-689.865	± 0.039	kJ/mol	61.0174 ± 0.0012	71-52-3*800
5.1	Benzoic acid	C6H5C(O)OH (g)	-274.33	-294.13	± 0.19	kJ/mol	122.1213 ± 0.0056	65-85-0*0

Most Influential reactions involving (C(O)OH)2 (cr)

Please note: The list, which is based on a hat (projection) matrix analysis, is limited to no more than 20 largest influences.

Influence Coefficient	TN ID	Reaction	Measured Quantity	Reference
0.792	5298.2	(C(O)OH)2 (cr) + 1/2 O2 (g) → 2 CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -58.13 ± 0.11 kcal/mol	Brown 1968
0.181	5298.1	(C(O)OH)2 (cr) + 1/2 O2 (g) → 2 CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -58.06 ± 0.23 kcal/mol	Wilhoit 1964
0.160	5299.2	(C(O)OH)2 (cr) → (C(O)OH)2 (g)	Δ_rH°(322 K) = 98.5 ± 3 kJ/mol	de Wit 1983b, est unc
0.090	5299.1	(C(O)OH)2 (cr) → (C(O)OH)2 (g)	Δ_rH°(298.15 K) = 100 ± 4 kJ/mol	Bilde 2015
0.082	5299.3	(C(O)OH)2 (cr) → (C(O)OH)2 (g)	Δ_rH°(316.5 K) = 23.47 ± 1 kcal/mol	Bradley 1953a, Bradley 1953, est unc

References

1		B. Ruscic, R. E. Pinzon, M. L. Morton, G. von Laszewski, S. Bittner, S. G. Nijsure, K. A. Amin, M. Minkoff, and A. F. Wagner, Introduction to Active Thermochemical Tables: Several "Key" Enthalpies of Formation Revisited. J. Phys. Chem. A 108, 9979-9997 (2004) [DOI: 10.1021/jp047912y]
2		B. Ruscic, R. E. Pinzon, G. von Laszewski, D. Kodeboyina, A. Burcat, D. Leahy, D. Montoya, and A. F. Wagner, Active Thermochemical Tables: Thermochemistry for the 21^st Century. J. Phys. Conf. Ser. 16, 561-570 (2005) [DOI: 10.1088/1742-6596/16/1/078]
3		B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.156 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		N. A. Seifert, B. Ruscic, R. Sivaramakrishnan, and K. Prozument, The C2H4O Isomers in the Oxidation of Ethylene J. Mol. Spectrosc. 398, 111847/1-8 (2023) [DOI: 10.1016/j.jms.2023.111847]
5		U. Jacovella, B. Ruscic, N. L. Chen, H.-L. Le, S. Boyé-Péronne, S. Hartweg, M. Roy-Chowdhury, G. A. Garcia, J.-C. Loison, and B. Gans, Refining Thermochemical Properties of CF, SiF, and Their Cations by Combining Photoelectron Spectroscopy, Quantum Chemical Calculations, and the Active Thermochemical Tables Approach Phys. Chem. Chem. Phys. 25, 30838-30847 (2023) [DOI: 10.1039/D3CP04244H]
6		B. Ruscic, Uncertainty Quantification in Thermochemistry, Benchmarking Electronic Structure Computations, and Active Thermochemical Tables. Int. J. Quantum Chem. 114, 1097-1101 (2014) [DOI: 10.1002/qua.24605]
7		B. Ruscic and D. H. Bross, Thermochemistry Computer Aided Chem. Eng. 45, 3-114 (2019) [DOI: 10.1016/B978-0-444-64087-1.00001-2]

Formula

The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.

Uncertainties

The listed uncertainties correspond to estimated 95% confidence limits, as customary in thermochemistry (see, for example, Ruscic [6] and Ruscic and Bross[7]).
Note that an uncertainty of ± 0.000 kJ/mol indicates that the estimated uncertainty is < ± 0.000₅ kJ/mol.

Website Functionality Credits

The reorganization of the website was developed and implemented by David H. Bross (ANL).
The find function is based on the complete Species Dictionary entries for the appropriate version of the ATcT TN.
The molecule images are rendered by Indigo-depict.
The XYZ renderings are based on Jmol: an open-source Java viewer for chemical structures in 3D. http://www.jmol.org/.

Acknowledgement

This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Contract No. DE-AC02-06CH11357.