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].

Hydrazoic acid

Formula: HNNN (aq)

CAS RN: 7782-79-8

ATcT ID: 7782-79-8*800

SMILES: N=[N+]=[N-]

InChI: InChI=1S/HN3/c1-3-2/h1H

InChIKey: JUINSXZKUKVTMD-UHFFFAOYSA-N

Hills Formula: H1N3

2D Image:

Aliases: HNNN; Hydrazoic acid; Hydrogen azide; Azidic acid; Azoimide; Diazoimide; Hydronitric acid; Triazoic acid; NNNH

Relative Molecular Mass: 43.02816 ± 0.00022

Δ_fH°(0 K)	Δ_fH°(298.15 K)	Uncertainty	Units
	272.69	± 0.47	kJ/mol

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

The 20 contributors listed below account only for 87.7% of the provenance of Δ_fH° of HNNN (aq).
A total of 28 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
29.0	2133.1	2 [NNN]- (aq) + [I3]- (aq) → 3 N2 (g) + 3 I- (aq)	Δ_rH°(298.15 K) = -158.78 ± 0.2 kcal/mol	Gray 1956
19.5	1357.1	I2 (cr,l) + I- (aq) → [I3]- (aq)	Δ_rH°(298.15 K) = 1.338 ± 0.256 kcal/mol	Wu 1963
9.7	1356.1	Br2 (cr,l) + 3 I- (aq) → [I3]- (aq) + 2 Br- (aq)	Δ_rH°(298.15 K) = -29.355 ± 0.364 kcal/mol	Wu 1963
8.7	2112.11	HNNN (g) → H (g) + 3 N (g)	Δ_rH°(0 K) = 318.06 ± 0.30 kcal/mol	Karton 2011
3.1	2130.2	HNNN (g) → HNNN (aq, undissoc)	Δ_rG°(298.15 K) = -1.5 ± 0.1 kcal/mol	D'Orazio 1963, as quoted by NBS Tables
3.1	2130.1	HNNN (g) → HNNN (aq, undissoc)	Δ_rH°(298.15 K) = -8.1 ± 0.1 kcal/mol	D'Orazio 1963, as quoted by NBS Tables
2.6	2119.1	HNNN (g) → 1/2 H2 (g) + 3/2 N2 (g)	Δ_rH°(285.6 K) = -70.3 ± 0.5 (×1.091) kcal/mol	Gunther 1935, apud Gurvich TPIS, as quoted by NBS Tables
2.5	2112.10	HNNN (g) → H (g) + 3 N (g)	Δ_rH°(0 K) = 317.83 ± 0.56 kcal/mol	Karton 2011
1.9	2120.1	HNNN (g) → H (g) + NNN (g)	Δ_rH°(0 K) = 30970 ± 50 cm-1	Cook 1999
1.5	2112.13	HNNN (g) → H (g) + 3 N (g)	Δ_rH°(0 K) = 1330.1 ± 3.0 kJ/mol	Klopper 2010a
1.1	1358.1	Cl2 (g) + 3 I- (aq) → 2 Cl- (aq) + [I3]- (aq)	Δ_rH°(298.15 K) = -51.5 ± 1.1 kcal/mol	Wartenberg 1930, Wartenberg 1931, Parker 1965
1.0	2131.2	HNNN (aq, undissoc) → HNNN (aq)	Δ_rH°(298.15 K) = 3.60 ± 0.05 kcal/mol	Gray 1956
0.5	2112.12	HNNN (g) → H (g) + 3 N (g)	Δ_rH°(0 K) = 316.66 ± 1 (×1.189) kcal/mol	Gutowski 2006
0.4	1445.11	NNN (g) → N2 (g) + N (g)	Δ_rH°(0 K) = 4.00 ± 1.0 kcal/mol	Dixon 2004
0.4	1440.9	NNN (g) → 3 N (g)	Δ_rH°(0 K) = 228.34 ± 1.0 kcal/mol	Dixon 2004
0.4	2120.2	HNNN (g) → H (g) + NNN (g)	Δ_rH°(0 K) = 30920 ± 100 cm-1	Yuan 2008
0.4	1304.1	HI (g) → HI (aq, 5130 H2O)	Δ_rH°(298.15 K) = -19.862 ± 0.020 kcal/mol	Vanderzee 1974
0.4	2112.9	HNNN (g) → H (g) + 3 N (g)	Δ_rH°(0 K) = 317.09 ± 1.35 kcal/mol	Karton 2011
0.3	2112.8	HNNN (g) → H (g) + 3 N (g)	Δ_rH°(0 K) = 317.66 ± 1.50 kcal/mol	Ruscic W1RO
0.3	1446.4	NNN (g) + CO (g) + [O2]+ (g) → [CO2]+ (g) + N2 (g) + NO (g)	Δ_rH°(0 K) = -114.03 ± 1.2 kcal/mol	Ruscic W1RO

Top 10 species with enthalpies of formation correlated to the Δ_fH° of HNNN (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	Azide	[NNN]- (aq)		272.69	± 0.47	kJ/mol	42.02077 ± 0.00021	14343-69-2*800
94.5	Hydrazoic acid	HNNN (aq, undissoc)		257.70	± 0.48	kJ/mol	43.02816 ± 0.00022	7782-79-8*1000
78.0	Hydrazoic acid	HNNN (g)	297.99	291.69	± 0.48	kJ/mol	43.02816 ± 0.00022	7782-79-8*0
58.8	Hydrazoic acid	HNNN (cr,l)		261.57	± 0.64	kJ/mol	43.02816 ± 0.00022	7782-79-8*500
49.7	Azido radical	NNN (g)	452.38	449.79	± 0.59	kJ/mol	42.02022 ± 0.00021	12596-60-0*0
43.5	Hydrazoic acid cation	[HNNN]+ (g)	1333.73	1328.06	± 0.82	kJ/mol	43.02761 ± 0.00022	58852-14-5*0
27.8	Trinitrogen cation	[NNN]+ (g)	1519.59	1516.96	± 0.89	kJ/mol	42.01967 ± 0.00021	12185-03-4*0
26.7	Azide	[NNN]- (g)	193.63	190.13	± 0.91	kJ/mol	42.02077 ± 0.00021	14343-69-2*0
19.0	Cyanic azide	NCNNN (g)	502.8	498.3	± 1.9	kJ/mol	68.03766 ± 0.00085	764-05-6*0
-59.1	Triiodide	[I3]- (aq)		-51.53	± 0.79	kJ/mol	380.713959 ± 0.000090	14900-04-0*800

Most Influential reactions involving HNNN (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	2132.1	HNNN (aq) → [NNN]- (aq) + H+ (aq)	Δ_rH°(298.15 K) = 0.000 ± 0.000 kJ/mol	triv
0.555	2131.2	HNNN (aq, undissoc) → HNNN (aq)	Δ_rH°(298.15 K) = 3.60 ± 0.05 kcal/mol	Gray 1956
0.139	2131.1	HNNN (aq, undissoc) → HNNN (aq)	Δ_rH°(298.15 K) = 3.6 ± 0.1 kcal/mol	D'Orazio 1963, as quoted by NBS Tables
0.139	2131.4	HNNN (aq, undissoc) → HNNN (aq)	Δ_rG°(298.15 K) = 6.3 ± 0.1 kcal/mol	D'Orazio 1963, as quoted by NBS Tables
0.139	2131.5	HNNN (aq, undissoc) → HNNN (aq)	Δ_rG°(298.15 K) = 6.2 ± 0.1 kcal/mol	Quintin 1940, Gray 1956

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.