Selected ATcT [1, 2] enthalpy of formation based on version 1.176 of the Thermochemical Network [3]

This version of ATcT results[3] was generated by additional expansion of version 1.172 to include species related to Criegee intermediates that are involved in several ongoing studies[4].

Sulfuric acid heptahydrate

Formula: (OS(O)(OH)2)(H2O)7 (cr,l)

CAS RN: 137168-51-5

ATcT ID: 137168-51-5*500

SMILES: OS(=O)(=O)O.O.O.O.O.O.O.O

InChI: InChI=1S/H2O4S.7H2O/c1-5(2,3)4;;;;;;;/h(H2,1,2,3,4);7*1H2

InChIKey: RVUXIPACAZKWHU-UHFFFAOYSA-N

Hills Formula: H16O11S1

2D Image:

Aliases: (OS(O)(OH)2)(H2O)7; Sulfuric acid heptahydrate; Hydrogen sulfate heptahydrate; (O2S(OH)2)(H2O)7; ((O2S)(OH)2)(H2O)7; ((SO2)(OH)2)(H2O)7; (S(O)(O)(OH)2)(H2O)7; (S(O)2(OH)2)(H2O)7; (H2SO4)(H2O)7; H2SO4.7H2O

Relative Molecular Mass: 224.1864 ± 0.0069

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
	-2876.89	± 0.22	kJ/mol

Top contributors to the provenance of Δ_fH° of (OS(O)(OH)2)(H2O)7 (cr,l)

The 20 contributors listed below account only for 70.8% of the provenance of Δ_fH° of (OS(O)(OH)2)(H2O)7 (cr,l).
A total of 173 contributors would be needed to account for 90% of the provenance.

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
19.9	125.2	1/2 O2 (g) + H2 (g) → H2O (cr,l)	Δ_rH°(298.15 K) = -285.8261 ± 0.040 kJ/mol	Rossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
10.9	9416.1	S (cr,l) + O2 (g) → OSO (g)	Δ_rH°(298.15 K) = -296.847 ± 0.200 kJ/mol	Eckman 1929, note SO2
7.2	9563.1	S (cr,l) + 3/2 O2 (g) + H2O (cr,l) → OS(O)(OH)2 (aq, 115 H2O)	Δ_rH°(298.15 K) = -143.85 ± 0.06 kcal/mol	Good 1960, CODATA Key Vals
5.9	2373.7	CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l)	Δ_rH°(298.15 K) = -890.578 ± 0.078 kJ/mol	Schley 2010
5.4	2375.1	2 H2 (g) + C (graphite) → CH4 (g)	Δ_rG°(1165 K) = 37.521 ± 0.068 kJ/mol	Smith 1946, note COf, 3rd Law
5.3	9563.2	S (cr,l) + 3/2 O2 (g) + H2O (cr,l) → OS(O)(OH)2 (aq, 115 H2O)	Δ_rH°(298.15 K) = -143.92 ± 0.07 kcal/mol	Mansson 1963, CODATA Key Vals
2.1	9602.1	S (cr,l) + 3/2 O2 (g) + H2O (cr,l) → OS(O)(OH)2 (aq, 45 H2O)	Δ_rH°(298.15 K) = -143.67 ± 0.11 kcal/mol	McCullough 1957a
1.4	9562.1	S (cr,l) + 3/2 O2 (g) + H2O (cr,l) → OS(O)(OH)2 (aq, 70 H2O)	Δ_rH°(298.15 K) = -143.58 ± 0.09 (×1.477) kcal/mol	McCullough 1953, CODATA Key Vals
1.4	115.11	H2O (g) → O (g) + 2 H (g)	Δ_rH°(0 K) = 917.80 ± 0.15 kJ/mol	Thorpe 2021
1.3	9401.2	2 S (cr,l) → S2 (g)	Δ_rG°(570 K) = 9.483 ± 0.138 (×1.915) kcal/mol	Drowart 1968, Detry 1967, 3rd Law
1.2	157.1	OH (g) → [OH]+ (g)	Δ_rH°(0 K) = 104989 ± 5 (×2.378) cm-1	Wiedmann 1992, note unc
1.0	167.6	H2O (g) → [OH]+ (g) + H (g)	Δ_rH°(0 K) = 18.1183 ± 0.0015 (×1.067) eV	Bodi 2014
1.0	9401.4	2 S (cr,l) → S2 (g)	Δ_rG°(600 K) = 8.57 ± 0.29 (×1.044) kcal/mol	Braune 1951, West 1929, Gurvich TPIS, 3rd Law
1.0	9563.3	S (cr,l) + 3/2 O2 (g) + H2O (cr,l) → OS(O)(OH)2 (aq, 115 H2O)	Δ_rH°(298.15 K) = -143.70 ± 0.07 (×2.278) kcal/mol	Waddington 1956, Mansson 1963, est unc
0.9	152.1	OH (g) → O (g) + H (g)	Δ_rH°(0 K) = 35580 ± 15 cm-1	Sun 2020
0.9	1731.1	N2 (g) + 3 H2O (cr,l) + 2 H+ (aq) → 3/2 O2 (g) + 2 [NH4]+ (aq)	Δ_rH°(298.15 K) = 141.292 ± 0.119 kcal/mol	Vanderzee 1972c
0.8	169.1	[OH]- (g) → O- (g) + H (g)	Δ_rH°(0 K) = 4.7796 ± 0.0010 (×2) eV	Martin 2001, est unc
0.8	2373.4	CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l)	Δ_rH°(298.15 K) = -890.61 ± 0.21 kJ/mol	Dale 2002
0.7	2268.11	CO (g) → C (g) + O (g)	Δ_rH°(0 K) = 1071.92 ± 0.10 kJ/mol	Thorpe 2021
0.7	9561.1	OSO (g) + 1/2 O2 (g) + H2O (cr,l) → OS(O)(OH)2 (cr,l)	Δ_rH°(298.15 K) = -231.329 ± 0.040 kJ/mol	NBS Tables 1989

Top 10 species with enthalpies of formation correlated to the Δ_fH° of (OS(O)(OH)2)(H2O)7 (cr,l)

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
99.8	Sulfuric acid octahydrate	(OS(O)(OH)2)(H2O)8 (cr,l)		-3164.40	± 0.24	kJ/mol	242.2017 ± 0.0071	88434-16-6*500
99.7	Sulfuric acid hexahydrate	(OS(O)(OH)2)(H2O)6 (cr,l)		-2588.94	± 0.20	kJ/mol	206.1712 ± 0.0068	137168-50-4*500
99.4	Sulfuric acid nonahydrate	(OS(O)(OH)2)(H2O)9 (cr,l)		-3451.56	± 0.25	kJ/mol	260.2170 ± 0.0073	137168-52-6*500
99.0	Sulfuric acid decahydrate	(OS(O)(OH)2)(H2O)10 (cr,l)		-3738.46	± 0.27	kJ/mol	278.2323 ± 0.0075	137168-53-7*500
98.9	Sulfuric acid pentahydrate	(OS(O)(OH)2)(H2O)5 (cr,l)		-2300.39	± 0.18	kJ/mol	188.1559 ± 0.0066	137168-49-1*500
97.9	Sulfuric acid dodecahydrate	(OS(O)(OH)2)(H2O)12 (cr,l)		-4311.68	± 0.31	kJ/mol	314.2628 ± 0.0079	30383-99-4*500
97.3	Sulfuric acid tetrahydrate	(OS(O)(OH)2)(H2O)4 (cr,l)	-2006.95	-2010.99	± 0.17	kJ/mol	170.1406 ± 0.0065	37006-20-5*500
96.2	Sulfuric acid pentadecahydrate	(OS(O)(OH)2)(H2O)15 (cr,l)		-5170.58	± 0.37	kJ/mol	368.3087 ± 0.0086	425605-43-2*500
94.2	Sulfuric acid trihydrate	(OS(O)(OH)2)(H2O)3 (cr,l)	-1716.10	-1720.21	± 0.15	kJ/mol	152.1253 ± 0.0064	40835-65-2*500
89.2	Sulfuric acid dihydrate	(OS(O)(OH)2)(H2O)2 (cr,l)	-1422.15	-1426.94	± 0.14	kJ/mol	134.1100 ± 0.0063	13451-10-0*500

Most Influential reactions involving (OS(O)(OH)2)(H2O)7 (cr,l)

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	9644.1	(OS(O)(OH)2)(H2O)7 (cr,l) → OS(O)(OH)2 (cr,l) + 7 H2O (cr,l)	Δ_rH°(298.15 K) = 62.384 ± 0.004 kJ/mol	CODATA Key Vals, NBS TN270

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. 1.176 of the Thermochemical Network (2024); available at ATcT.anl.gov
4		T. L. Nguyen et al, ongoing studies (2024)
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.