Selected ATcT [1, 2] enthalpy of formation based on version 1.122o of the Thermochemical Network [3] This version of ATcT results was generated from an expansion of version 1.122h [4] to include the ionization energy of H2O2. [5].
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Species Name |
Formula |
Image |
ΔfH°(0 K) |
ΔfH°(298.15 K) |
Uncertainty |
Units |
Relative Molecular Mass |
ATcT ID |
Ammonia | NH3 (aq, undissoc) | | | -80.885 | ± 0.053 | kJ/mol | 17.03056 ± 0.00022 | 7664-41-7*1000 |
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Top contributors to the provenance of ΔfH° of NH3 (aq, undissoc)The 13 contributors listed below account for 90.5% 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.
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Contribution (%) | TN ID | Reaction | Measured Quantity | Reference | 37.2 | 1435.1 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.448 ± 0.015 kcal/mol | Vanderzee 1972 | 12.7 | 1382.1 | 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g)  | ΔrH°(298.15 K) = -10.885 ± 0.010 kcal/mol | Larson 1923, Vanderzee 1972 | 9.3 | 1435.2 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/mol | Stavaley 1971, Vanderzee 1972, as quoted by CODATA Key Vals | 9.3 | 1435.7 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/mol | Staveley 1971, Vanderzee 1972 | 6.5 | 1381.5 | 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g)  | ΔrH°(298.15 K) = -10.875 ± 0.014 kcal/mol | Schulz 1966, Vanderzee 1972 | 3.9 | 1444.1 | 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/mol | Vanderzee 1972c | 3.3 | 1435.3 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.442 ± 0.050 kcal/mol | Thomsen 1873, Vanderzee 1972 | 2.7 | 1381.4 | 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g)  | ΔrH°(298.15 K) = -10.910 ± 0.015 (×1.445) kcal/mol | Larson 1924, Vanderzee 1972 | 1.6 | 1443.1 | NH3 (g) + HON(O)O (aq) → [NH4]+ (aq) + [ON(O)O]- (aq)  | ΔrH°(298.15 K) = -87.23 ± 0.25 (×1.164) kJ/mol | Becker 1934, Vanderzee 1972a, as quoted by CODATA Key Vals | 1.0 | 1440.3 | (NH4)NO3 (cr,l) → N2 (g) + 1/2 O2 (g) + 2 H2O (cr,l)  | ΔrH°(293.65 K) = -49.44 ± 0.06 kcal/mol | Becker 1934 | 0.9 | 1444.3 | 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/mol | Becker 1934, as quoted by CODATA Key Vals | 0.9 | 1382.8 | 1/2 N2 (g) + 3/2 H2 (g) → NH3 (g)  | ΔrG°(635 K) = 20.084 ± 0.157 kJ/mol | Schulz 1966, 3rd Law | 0.8 | 1435.4 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.475 ± 0.100 kcal/mol | Baud 1909, Vanderzee 1972 |
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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.
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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) | | | -133.075 | ± 0.056 | kJ/mol | 18.03795 ± 0.00029 | 14798-03-9*800 | 90.5 | Ammonium hydroxide | NH4OH (aq, undissoc) | | | -366.716 | ± 0.062 | kJ/mol | 35.04584 ± 0.00047 | 1336-21-6*1000 | 83.4 | Ammonium chloride | (NH4)Cl (cr) | | -311.556 | -314.717 | ± 0.063 | kJ/mol | 53.49120 ± 0.00095 | 12125-02-9*510 | 51.4 | Ammonia | NH3 (g) | | -38.564 | -45.557 | ± 0.030 | kJ/mol | 17.03056 ± 0.00022 | 7664-41-7*0 | 51.4 | Azanylium | [NH3]+ (g) | | 944.273 | 937.318 | ± 0.030 | kJ/mol | 17.03001 ± 0.00022 | 19496-55-0*0 | 33.0 | Ammonium bromide | (NH4)Br (cr) | | -253.69 | -270.26 | ± 0.16 | kJ/mol | 97.9425 ± 0.0010 | 12124-97-9*510 | 16.2 | Ammonium nitrate | (NH4)NO3 (cr,l) | | -350.29 | -365.26 | ± 0.18 | kJ/mol | 80.04344 ± 0.00095 | 6484-52-2*500 | -12.6 | Nitric acid | HON(O)O (aq, 1000 H2O) | | | -206.32 | ± 0.18 | kJ/mol | 63.01288 ± 0.00091 | 7697-37-2*839 | -12.7 | Nitrate | [ON(O)O]- (aq) | | | -206.64 | ± 0.18 | kJ/mol | 62.00549 ± 0.00090 | 14797-55-8*800 | -12.7 | Nitric acid | HON(O)O (aq) | | | -206.64 | ± 0.18 | kJ/mol | 63.01288 ± 0.00091 | 7697-37-2*800 |
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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.
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Influence Coefficient | TN ID | Reaction | Measured Quantity | Reference | 1.000 | 1436.1 | NH3 (aq, undissoc) + H2O (cr,l) → NH4OH (aq, undissoc)  | ΔrH°(298.15 K) = 0.000 ± 0.000 kJ/mol | triv | 0.795 | 1441.1 | [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq)  | ΔrG°(298.15 K) = 52.771 ± 0.020 kJ/mol | Bates 1950, Bates 1949, Bates 1943, Bates 1946 | 0.530 | 1435.1 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.448 ± 0.015 kcal/mol | Vanderzee 1972 | 0.421 | 1555.2 | 3 NH2OH (aq, undissoc) → N2 (g) + NH3 (aq, undissoc) + 3 H2O (cr,l)  | ΔrH°(298.15 K) = -154.2 ± 2.4 kcal/mol | Thomsen 1882, Ellingson 1915, Berthelot 1877, Lumme 1965, Muhammad 1957, Svyentoslavskii 1909, Berthelot 1890, as quoted by NBS Tables | 0.421 | 1555.1 | 3 NH2OH (aq, undissoc) → N2 (g) + NH3 (aq, undissoc) + 3 H2O (cr,l)  | ΔrH°(298.15 K) = -153.7 ± 2.4 kcal/mol | Thomsen 1882, Ellingson 1915, Berthelot 1877, Lumme 1965, Muhammad 1957, Svyentoslavskii 1909, Berthelot 1890, as quoted by NBS Tables | 0.132 | 1435.2 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/mol | Stavaley 1971, Vanderzee 1972, as quoted by CODATA Key Vals | 0.132 | 1435.7 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.456 ± 0.030 kcal/mol | Staveley 1971, Vanderzee 1972 | 0.127 | 1441.5 | [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq)  | ΔrG°(298.15 K) = 52.732 ± 0.050 kJ/mol | Everett 1954, Olofsson 1975a, as quoted by CODATA Key Vals | 0.047 | 1435.3 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.442 ± 0.050 kcal/mol | Thomsen 1873, Vanderzee 1972 | 0.027 | 1442.2 | NH3 (aq, undissoc) + H2O (cr,l) → [NH4]+ (aq) + [OH]- (aq)  | ΔrH°(298.15 K) = 0.865 ± 0.030 kcal/mol | Pitzer 1937 | 0.022 | 1441.2 | [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq)  | ΔrH°(298.15 K) = 52.201 ± 0.118 kJ/mol | Bates 1950, Bates 1949, Bates 1943, Bates 1946 | 0.011 | 1435.4 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.475 ± 0.100 kcal/mol | Baud 1909, Vanderzee 1972 | 0.008 | 1442.3 | NH3 (aq, undissoc) + H2O (cr,l) → [NH4]+ (aq) + [OH]- (aq)  | ΔrH°(298.15 K) = 0.920 ± 0.010 (×5.417) kcal/mol | Vanderzee 1972a | 0.005 | 1442.1 | NH3 (aq, undissoc) + H2O (cr,l) → [NH4]+ (aq) + [OH]- (aq)  | ΔrH°(298.15 K) = 0.800 ± 0.030 (×2.229) kcal/mol | Pitzer 1937, Vanderzee 1972a | 0.005 | 1435.5 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.320 ± 0.150 kcal/mol | Wrewsky 1924, Vanderzee 1972 | 0.004 | 1441.6 | [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq)  | ΔrH°(298.15 K) = 51.92 ± 0.11 (×2.484) kJ/mol | Olofsson 1975a, Parker 1965, as quoted by CODATA Key Vals | 0.002 | 1441.8 | [NH4]+ (aq) → NH3 (aq, undissoc) + H+ (aq)  | ΔrH°(298.15 K) = 51.798 ± 0.314 (×1.269) kJ/mol | Everett 1954 | 0.001 | 1435.6 | NH3 (g) → NH3 (aq, undissoc)  | ΔrH°(298.15 K) = -8.160 ± 0.150 (×1.915) kcal/mol | Ramstetter 1931, Vanderzee 1972 |
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References
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1
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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]
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2
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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]
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3
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B. Ruscic and D. H. Bross, Active Thermochemical Tables (ATcT) values based on ver. 1.122o of the Thermochemical Network (2020); available at ATcT.anl.gov |
4
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Y.-C. Chang, B. Xiong, D. H. Bross, B. Ruscic, and C. Y. Ng,
A Vacuum Ultraviolet laser Pulsed Field Ionization-Photoion Study of Methane (CH4): Determination of the Appearance Energy of Methylium From Methane with Unprecedented Precision and the Resulting Impact on the Bond Dissociation Energies of CH4 and CH4+.
Phys. Chem. Chem. Phys. 19, 9592-9605 (2017)
[DOI: 10.1039/c6cp08200a] (part of 2017 PCCP Hot Articles collection)
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5
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P. B. Changala, T. L. Nguyen, J. H. Baraban, G. B. Ellison, J. F. Stanton, D. H. Bross, and B. Ruscic,
Active Thermochemical Tables: The Adiabatic Ionization Energy of Hydrogen Peroxide.
J. Phys. Chem. A 121, 8799-8806 (2017)
[DOI: 10.1021/acs.jpca.7b06221] (highlighted on the journal cover)
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6
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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]
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Formula
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The aggregate state is given in parentheses following the formula, such as: g - gas-phase, cr - crystal, l - liquid, etc.
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Uncertainties
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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.
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Website Functionality Credits
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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/.
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Acknowledgement
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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.
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