Selected ATcT [1, 2] enthalpy of formation based on version 1.122 of the Thermochemical Network [3]

This version of ATcT results was partially described in Ruscic et al. [4], and was also used for the initial development of high-accuracy ANLn composite electronic structure methods [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
AmmoniaNH3 (aq, undissoc)N-80.886± 0.053kJ/mol17.03056 ±
0.00022		7664-41-7*1000

Top contributors to the provenance of ΔfH° of NH3 (aq, undissoc)

The 13 contributors listed below account for 90.4% of the provenance of ΔfH° of NH3 (aq, undissoc).

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
36.91199.1 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.448 ± 0.015 kcal/molVanderzee 1972
13.01149.1 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.885 ± 0.010 kcal/molLarson 1923, Vanderzee 1972
9.21199.2 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/molStavaley 1971, Vanderzee 1972, as quoted by CODATA Key Vals
9.21199.7 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/molStaveley 1971, Vanderzee 1972
6.61148.5 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.875 ± 0.014 kcal/molSchulz 1966, Vanderzee 1972
3.91208.1 N2 (g) + 3 H2O (cr,l) + 2 H+ (aq) → 3/2 O2 (g) + 2 [NH4]+ (aq) ΔrH°(298.15 K) = 141.292 ± 0.119 kcal/molVanderzee 1972c
3.31199.3 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.442 ± 0.050 kcal/molThomsen 1873, Vanderzee 1972
2.51148.4 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrH°(298.15 K) = -10.910 ± 0.015 (×1.509) kcal/molLarson 1924, Vanderzee 1972
1.51207.1 NH3 (g) + HNO3 (aq) → [NH4]+ (aq) + [NO3]- (aq) ΔrH°(298.15 K) = -87.23 ± 0.25 (×1.189) kJ/molBecker 1934, Vanderzee 1972a, as quoted by CODATA Key Vals
0.91204.3 (NH4)NO3 (cr,l) → N2 (g) + 1/2 O2 (g) + 2 H2O (cr,l) ΔrH°(293.65 K) = -49.44 ± 0.06 kcal/molBecker 1934
0.91208.3 N2 (g) + 3 H2O (cr,l) + 2 H+ (aq) → 3/2 O2 (g) + 2 [NH4]+ (aq) ΔrH°(298.15 K) = 141.226 ± 0.239 kcal/molBecker 1934, as quoted by CODATA Key Vals
0.91201.7 (NH4)Cl (cr) → NH3 (g) + HCl (g) ΔrH°(298.15 K) = 42.43 ± 0.09 kcal/molRodebush 1929, JANAF 3, 2nd Law
0.91149.8 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g) ΔrG°(635 K) = 20.084 ± 0.157 kJ/molSchulz 1966, 3rd Law

Top 10 species with enthalpies of formation correlated to the ΔfH° of NH3 (aq, undissoc)

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 Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
94.6 Ammonium[NH4]+ (aq)[NH4+]-133.077± 0.056kJ/mol18.03795 ±
0.00029		14798-03-9*800
90.3 Ammonium hydroxideNH4OH (aq, undissoc)[NH4+].[OH-]-366.715± 0.062kJ/mol35.04584 ±
0.00047		1336-21-6*1000
83.3 Ammonium chloride(NH4)Cl (cr)[NH4+].[Cl-]-311.724-314.886± 0.063kJ/mol53.49120 ±
0.00095		12125-02-9*510
51.7 AmmoniaNH3 (g)N-38.562-45.554± 0.030kJ/mol17.03056 ±
0.00022		7664-41-7*0
51.7 Aminium[NH3]+ (g)[NH3+]944.275937.320± 0.030kJ/mol17.03001 ±
0.00022		19496-55-0*0
30.1 Ammonium bromide(NH4)Br (cr)[NH4+].[Br-]-253.56-270.14± 0.17kJ/mol97.9425 ±
0.0010		12124-97-9*510
16.0 Ammonium nitrate(NH4)NO3 (cr,l)[NH4+].O=[N+]([O-])[O-]-350.28-365.25± 0.19kJ/mol80.04344 ±
0.00095		6484-52-2*500
-12.6 Nitric acidHNO3 (aq, 1000 H2O)O[N+](=O)[O-]-206.31± 0.18kJ/mol63.01288 ±
0.00091		7697-37-2*839
-12.7 Nitrate[NO3]- (aq)O=[N+]([O-])[O-]-206.63± 0.18kJ/mol62.00549 ±
0.00090		14797-55-8*800
-12.7 Nitric acidHNO3 (aq)O[N+](=O)[O-]-206.63± 0.18kJ/mol63.01288 ±
0.00091		7697-37-2*800

Most Influential reactions involving NH3 (aq, undissoc)

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
1.0001200.1 NH3 (aq, undissoc) + H2O (cr,l) → NH4OH (aq, undissoc) ΔrH°(298.15 K) = 0.000 ± 0.000 kJ/moltriv
0.7941205.1 [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq) ΔrG°(298.15 K) = 52.771 ± 0.020 kJ/molBates 1950, Bates 1949, Bates 1943, Bates 1946
0.5281199.1 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.448 ± 0.015 kcal/molVanderzee 1972
0.4231314.1 3 NH2OH (aq, undissoc) → N2 (g) + NH3 (aq, undissoc) + 3 H2O (cr,l) ΔrH°(298.15 K) = -153.7 ± 2.4 kcal/molThomsen 1882, Ellingson 1915, Berthelot 1877, Lumme 1965, Muhammad 1957, Svyentoslavskii 1909, Berthelot 1890, as quoted by NBS Tables
0.4231314.2 3 NH2OH (aq, undissoc) → N2 (g) + NH3 (aq, undissoc) + 3 H2O (cr,l) ΔrH°(298.15 K) = -154.2 ± 2.4 kcal/molThomsen 1882, Ellingson 1915, Berthelot 1877, Lumme 1965, Muhammad 1957, Svyentoslavskii 1909, Berthelot 1890, as quoted by NBS Tables
0.1321199.2 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/molStavaley 1971, Vanderzee 1972, as quoted by CODATA Key Vals
0.1321199.7 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/molStaveley 1971, Vanderzee 1972
0.1271205.5 [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq) ΔrG°(298.15 K) = 52.732 ± 0.050 kJ/molEverett 1954, Olofsson 1975a, as quoted by CODATA Key Vals
0.0471199.3 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.442 ± 0.050 kcal/molThomsen 1873, Vanderzee 1972
0.0271206.2 NH3 (aq, undissoc) + H2O (cr,l) → [NH4]+ (aq) + [OH]- (aq) ΔrH°(298.15 K) = 0.865 ± 0.030 kcal/molPitzer 1937
0.0221205.2 [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq) ΔrH°(298.15 K) = 52.201 ± 0.118 kJ/molBates 1950, Bates 1949, Bates 1943, Bates 1946
0.0111199.4 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.475 ± 0.100 kcal/molBaud 1909, Vanderzee 1972
0.0081206.3 NH3 (aq, undissoc) + H2O (cr,l) → [NH4]+ (aq) + [OH]- (aq) ΔrH°(298.15 K) = 0.920 ± 0.010 (×5.417) kcal/molVanderzee 1972a
0.0051206.1 NH3 (aq, undissoc) + H2O (cr,l) → [NH4]+ (aq) + [OH]- (aq) ΔrH°(298.15 K) = 0.800 ± 0.030 (×2.229) kcal/molPitzer 1937, Vanderzee 1972a
0.0051199.5 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.320 ± 0.150 kcal/molWrewsky 1924, Vanderzee 1972
0.0041205.6 [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq) ΔrH°(298.15 K) = 51.92 ± 0.11 (×2.484) kJ/molOlofsson 1975a, Parker 1965, as quoted by CODATA Key Vals
0.0021205.8 [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq) ΔrH°(298.15 K) = 51.798 ± 0.314 (×1.269) kJ/molEverett 1954
0.0011199.6 NH3 (g) → NH3 (aq, undissoc) ΔrH°(298.15 K) = -8.160 ± 0.150 (×1.915) kcal/molRamstetter 1931, Vanderzee 1972
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 21st 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. 1.122 of the Thermochemical Network (2016); available at ATcT.anl.gov
4   B. Ruscic,
Active Thermochemical Tables: Sequential Bond Dissociation Enthalpies of Methane, Ethane, and Methanol and the Related Thermochemistry.
J. Phys. Chem. A 119, 7810-7837 (2015) [DOI: 10.1021/acs.jpca.5b01346]
5   S. J. Klippenstein, L. B. Harding, and B. Ruscic,
Ab initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species.
J. Phys. Chem. A 121, 6580-6602 (2017) [DOI: 10.1021/acs.jpca.7b05945]
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]
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]).
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.