Selected ATcT [1, 2] enthalpy of formation based on version 1.172 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.156 to include species relevant to a study of photodissociation of formamide[4].

Hypochlorous acid

Formula: HOCl (aq)

CAS RN: 7790-92-3

ATcT ID: 7790-92-3*800

SMILES: OCl

InChI: InChI=1S/ClHO/c1-2/h2H

InChIKey: QWPPOHNGKGFGJK-UHFFFAOYSA-N

Hills Formula: Cl1H1O1

2D Image:

Aliases: Hypochlorous acid; Hydrogen oxychloride; Pure Star MP 100000C; Chlorine hydroxide; Hydroxyl chloride; Hydroxychlorine; Hydroxidochlorine; ClOH; HOCl

Relative Molecular Mass: 52.46004 ± 0.00095

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
	-110.488	± 0.076	kJ/mol

Top contributors to the provenance of Δ_fH° of HOCl (aq)

The 2 contributors listed below account for 90.3% of the provenance of Δ_fH° of HOCl (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
55.9	1056.1	HOCl (aq, undissoc) → H+ (aq) + [ClO]- (aq)	Δ_rG°(298.15 K) = 43.019 ± 0.057 kJ/mol	Morris 1966
34.3	1052.1	HOCl (g) → HOCl (aq, undissoc)	Δ_rG°(298.15 K) = -16.067 ± 0.045 kJ/mol	Huthwelker 1995, Sander 2023, note unc

Top 10 species with enthalpies of formation correlated to the Δ_fH° of HOCl (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°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units	Relative Molecular Mass	ATcT ID
100.0	Hypochlorite	[ClO]- (aq)		-110.488	± 0.076	kJ/mol	51.45265 ± 0.00095	14380-61-1*1000
66.2	Hypochlorous acid	HOCl (aq, undissoc)		-125.526	± 0.050	kJ/mol	52.46004 ± 0.00095	7790-92-3*1000
30.1	Hypochlorous acid	HOCl (g)	-73.844	-76.784	± 0.023	kJ/mol	52.46004 ± 0.00095	7790-92-3*0
28.6	Hydroxyl	OH (g)	37.274	37.514	± 0.022	kJ/mol	17.00734 ± 0.00031	3352-57-6*0
28.6	Hydroxyde	[OH]- (g)	-139.068	-139.034	± 0.022	kJ/mol	17.00789 ± 0.00031	14280-30-9*0
28.6	Water	H2O (l, eq.press.)		-285.806	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*589
28.6	Water	H2O (g, ortho)	-238.622	-241.810	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*1
28.6	Water	H2O (g, para)	-238.907	-241.810	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*2
28.6	Water	H2O (g)	-238.907	-241.810	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*0
28.6	Water	H2O (l)		-285.804	± 0.022	kJ/mol	18.01528 ± 0.00033	7732-18-5*590

Most Influential reactions involving HOCl (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	1055.1	HOCl (aq) → H+ (aq) + [ClO]- (aq)	Δ_rH°(298.15 K) = 0 ± 0 cm-1	triv

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. 1.172 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		K. L. Caster, N. A. Seifert, B. Ruscic, A. W. Jasper, and K. Prozument, Dynamics of HCN, NHC, and HNCO Formation in the 193 nm Photodissociation of Formamide J. Phys. Chem. A (in press) (2024) [DOI: 10.1021/acs.jpca.4c02232]
5		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]
6		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 [5] and Ruscic and Bross[6]).
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.