Selected ATcT [1, 2] enthalpy of formation based on version 1.124 of the Thermochemical Network [3]

This version of ATcT results was generated by additional expansion of version 1.122x [4] to include additional information relevant to the study of thermophysical and thermochemical properties of CH2 and CH3 using nonrigid rotor anharmonic oscillator (NRRAO) partition functions [5], the development and benchmarking of a state-of-the-art computational approach that aims to reproduce total atomization energies of small molecules within 10–15 cm^-1 [6], as well as the study of the reversible reaction C₂H₃ + H₂ ⇌ C₂H₄ + H ⇌ C₂H₅ [7]

Formic acid

Formula: HC(O)OH (aq)

CAS RN: 64-18-6

ATcT ID: 64-18-6*800

SMILES: C(=O)O

InChI: InChI=1S/CH2O2/c2-1-3/h1H,(H,2,3)

InChIKey: BDAGIHXWWSANSR-UHFFFAOYSA-N

Hills Formula: C1H2O2

2D Image:

Aliases: HC(O)OH; Formic acid; Hydrogen carboxylic acid; Methanoic acid; HCOOH; OCHOH; O=CH-OH; H(C=O)OH; Formylic acid; Aminic acid

Relative Molecular Mass: 46.0254 ± 0.0010

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
	-425.48	± 0.45	kJ/mol

Top contributors to the provenance of Δ_fH° of HC(O)OH (aq)

The 3 contributors listed below account for 93.3% of the provenance of Δ_fH° of HC(O)OH (aq).

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
80.3	4318.1	HC(O)OH (cr,l) → HC(O)OH (aq, undissoc)	Δ_rH°(298.15 K) = -0.71 ± 0.40 kJ/mol	NBS Tables 1989, NBS TN270
7.7	4316.2	HC(O)OH (cr,l) + 1/2 O2 (g) → CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -60.807 ± 0.074 kcal/mol	Lebedeva 1964
5.3	4316.1	HC(O)OH (cr,l) + 1/2 O2 (g) → CO2 (g) + H2O (cr,l)	Δ_rH°(298.15 K) = -60.851 ± 0.089 kcal/mol	Sinke 1959

Top 10 species with enthalpies of formation correlated to the Δ_fH° of HC(O)OH (aq)

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°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
100.0	Formate	[HC(O)O]- (aq)	-425.48	± 0.45	kJ/mol	45.0180 ± 0.0010	71-47-6*800
99.9	Formic acid	HC(O)OH (aq, undissoc)	-425.38	± 0.45	kJ/mol	46.0254 ± 0.0010	64-18-6*1000
74.4	Formic acid	HC(O)OH (aq, 15 H2O)	-425.20	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*817
74.4	Formic acid	HC(O)OH (aq, 1000 H2O)	-425.37	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*839
74.4	Formic acid	HC(O)OH (aq, 500 H2O)	-425.35	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*833
74.4	Formic acid	HC(O)OH (aq, 200 H2O)	-425.34	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*830
74.4	Formic acid	HC(O)OH (aq, 75 H2O)	-425.28	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*825
74.4	Formic acid	HC(O)OH (aq, 50 H2O)	-425.25	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*822
74.4	Formic acid	HC(O)OH (aq, 100 H2O)	-425.30	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*828
74.4	Formic acid	HC(O)OH (aq, 5 H2O)	-425.31	± 0.60	kJ/mol	46.0254 ± 0.0010	64-18-6*809

Most Influential reactions involving HC(O)OH (aq)

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
1.000	4321.1	HC(O)OH (aq) → [HC(O)O]- (aq) + H+ (aq)	Δ_rH°(298.15 K) = 0 ± 0 cm-1	triv
1.000	4322.1	HC(O)OH (aq, 100 H2O) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -0.18 ± 0.40 kJ/mol	NBS Tables 1989, NBS TN270
0.731	4320.5	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.429 ± 0.010 kJ/mol	Kinart 2019, 3rd Law, est unc
0.081	4320.3	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.43 ± 0.03 kJ/mol	Bell 1993, note unc2
0.045	4320.17	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.416 ± 0.040 kJ/mol	Robinson 1959, 3rd Law, est unc
0.045	4320.14	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.417 ± 0.040 kJ/mol	Harned 1934, 3rd Law, est unc
0.029	4320.13	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -0.063 ± 0.050 kJ/mol	Harned 1934, 2nd Law, est unc
0.029	4320.16	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -0.105 ± 0.050 kJ/mol	Robinson 1959, 2nd Law, est unc
0.011	4320.12	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.350 ± 0.080 kJ/mol	Partanen 2005, 3rd Law, est unc
0.007	4320.15	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.42 ± 0.10 kJ/mol	Harned 1930, 3rd Law, est unc
0.007	4320.8	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.34 ± 0.10 kJ/mol	Saxton 1940, 3rd Law, est unc
0.007	4320.10	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.326 ± 0.025 (×4.088) kJ/mol	Salomon 1986, 3rd Law, est unc
0.003	4320.11	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = 0.035 ± 0.150 kJ/mol	Partanen 2005, 2nd Law, est unc
0.000	4320.2	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -0.09 ± 0.30 kJ/mol	Bell 1993, note unc2
0.000	4320.1	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -0.12 ± 0.40 kJ/mol	NBS Tables 1989, NBS TN270
0.000	4320.7	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rG°(298.15 K) = 21.89 ± 0.14 (×3.364) kJ/mol	Boncina 2010, 3rd Law
0.000	4320.4	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -1.29 ± 0.50 (×2.43) kJ/mol	Kinart 2019, 2nd Law, est unc
0.000	4320.6	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -1.6 ± 0.5 (×3.018) kJ/mol	Boncina 2010, 2nd Law
0.000	4320.9	HC(O)OH (aq, undissoc) → HC(O)OH (aq)	Δ_rH°(298.15 K) = -1.02 ± 2.13 kJ/mol	Salomon 1986, 2nd Law, 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. 1.124 of the Thermochemical Network, Argonne National Laboratory, Lemont, Illinois 2022; available at ATcT.anl.gov [DOI: 10.17038/CSE/1885923]
4		Y. Ren, L. Zhou, A. Mellouki, V. Daële, M. Idir, S. S. Brown, B. Ruscic, Robert S. Paton, M. R. McGillen, and A. R. Ravishankara, Reactions of NO3 with Aromatic Aldehydes: Gas-Phase Kinetics and Insights into the Mechanism of the Reaction. Atmos. Chem. Phys. 21, 13537-13551 (2021) [DOI: 10.5194/acp2021-228]
5		B. Ruscic and D. H. Bross, Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects. Mol. Phys. e1969046 (2021) [DOI: 10.1080/00268976.2021.1969046]
6		J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton, Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions J. Chem. Phys. 155, 184109 (2021) [DOI: 10.1063/5.0069322]
7		T. L. Nguyen, D. H. Bross, B. Ruscic, G. B. Ellison, and J. F. Stanton, Mechanism, Thermochemistry, and Kinetics of the Reversible Reactions: C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5. Faraday Discuss. , (Advance Article) (2022) [DOI: 10.1039/D1FD00124H]
8		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]
9		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 [8,9]).
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.