Selected ATcT [1, 2] enthalpy of formation based on version 1.130 of the Thermochemical Network [3]

This version of ATcT results[4] was generated by additional expansion of version 1.128 [5,6] to include with the calculations provided in reference [4].

Urea

Formula: NH2C(O)NH2 (cr,l)
CAS RN: 57-13-6
ATcT ID: 57-13-6*500
SMILES: NC(=O)N
InChI: InChI=1S/CH4N2O/c2-1(3)4/h(H4,2,3,4)
InChIKey: XSQUKJJJFZCRTK-UHFFFAOYSA-N
Hills Formula: C1H4N2O1

2D Image:

NC(=O)N
Aliases: NH2C(O)NH2; Urea; Carbamide; Carbamimidic acid; Carbonyl diamide; Carbonyl diamine; Carbamoylamine
Relative Molecular Mass: 60.05534 ± 0.00091

   ΔfH°(0 K)   ΔfH°(298.15 K)UncertaintyUnits
-317.73-333.33± 0.12kJ/mol

Top contributors to the provenance of ΔfH° of NH2C(O)NH2 (cr,l)

The 7 contributors listed below account for 90.3% of the provenance of ΔfH° of NH2C(O)NH2 (cr,l).

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
39.17378.3 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(301.15 K) = -631.52 ± 0.16 kJ/molContineanu 1982, Johnson 1975
35.77378.6 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -150.99 ± 0.04 kcal/molHuffman 1940
6.57378.5 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -150.90 ± 0.05 (×1.874) kcal/molMansson 1963, as quoted by Cox 1970, note unc
3.9121.2 1/2 O2 (g) H2 (g) → H2O (cr,l) ΔrH°(298.15 K) = -285.8261 ± 0.040 kJ/molRossini 1939, Rossini 1931, Rossini 1931b, note H2Oa, Rossini 1930
2.27378.1 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -632.06 ± 0.67 kJ/molKabo 1990, Simirsky 1987
1.42279.1 H2 (g) C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
1.32277.7 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.578 ± 0.078 kJ/molSchley 2010

Top 10 species with enthalpies of formation correlated to the ΔfH° of NH2C(O)NH2 (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 Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass
ATcT ID
36.1 WaterH2O (cr,l)O-286.272-285.800± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*500
36.1 WaterH2O (g, ortho)O-238.617-241.805± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*1
36.1 WaterH2O (g, para)O-238.902-241.805± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*2
36.1 WaterH2O (g)O-238.902-241.805± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*0
36.1 WaterH2O (cr, l, eq.press.)O-286.274-285.801± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*499
36.1 WaterH2O (l, eq.press.)O-285.801± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*589
36.1 Oxonium[H3O]+ (aq)[OH3+]-285.800± 0.022kJ/mol19.02267 ±
0.00037
13968-08-6*800
36.1 WaterH2O (l)O-285.800± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*590
36.1 WaterH2O (cr)O-286.272-292.712± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*510
36.1 WaterH2O (cr, eq.press.)O-286.274-292.714± 0.022kJ/mol18.01528 ±
0.00033
7732-18-5*509

Most Influential reactions involving NH2C(O)NH2 (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
0.4637379.3 NH2C(O)NH2 (cr,l) → NH2C(O)NH2 (g) ΔrH°(351.3 K) = 96.9 ± 0.6 kJ/molde Wit 1983a, est unc
0.4597378.3 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(301.15 K) = -631.52 ± 0.16 kJ/molContineanu 1982, Johnson 1975
0.4197378.6 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -150.99 ± 0.04 kcal/molHuffman 1940
0.1667379.1 NH2C(O)NH2 (cr,l) → NH2C(O)NH2 (g) ΔrH°(366 K) = 97.6 ± 1.0 kJ/molKabo 1990
0.0767378.5 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -150.90 ± 0.05 (×1.874) kcal/molMansson 1963, as quoted by Cox 1970, note unc
0.0417379.2 NH2C(O)NH2 (cr,l) → NH2C(O)NH2 (g) ΔrH°(350 K) = 97.1 ± 2.0 kJ/molZaitsau 2003, Emelyanenko 2006, est unc
0.0267378.1 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -632.06 ± 0.67 kJ/molKabo 1990, Simirsky 1987
0.0027378.4 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -151.50 ± 0.40 (×1.297) kcal/molSunner 1946, as quoted by Cox 1970
0.0007378.2 NH2C(O)NH2 (cr,l) + 3/2 O2 (g) → 2 H2O (cr,l) CO2 (g) N2 (g) ΔrH°(298.15 K) = -645.0 ± 2.0 (×6.727) kJ/molContineanu 1982, Johnson 1975, note unc5


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. 1.130 of the Thermochemical Network. Argonne National Laboratory, Lemont, Illinois 2023; available at ATcT.anl.gov
[DOI: 10.17038/CSE/1997229]
4   N. Genossar, P. B. Changala, B. Gans, J.-C. Loison, S. Hartweg, M.-A. Martin-Drumel, G. A. Garcia, J. F. Stanton, B. Ruscic, and J. H. Baraban
Ring-Opening Dynamics of the Cyclopropyl Radical and Cation: the Transition State Nature of the Cyclopropyl Cation
J. Am. Chem. Soc. 144, 18518-18525 (2022) [DOI: 10.1021/jacs.2c07740]
5   B. Ruscic and D. H. Bross
Active Thermochemical Tables: The Thermophysical and Thermochemical Properties of Methyl, CH3, and Methylene, CH2, Corrected for Nonrigid Rotor and Anharmonic Oscillator Effects.
Mol. Phys. e1969046 (2021) [DOI: 10.1080/00268976.2021.1969046]
6   J. H. Thorpe, J. L. Kilburn, D. Feller, P. B. Changala, D. H. Bross, B. Ruscic, and J. F. Stanton,
Elaborated Thermochemical Treatment of HF, CO, N2, and H2O: Insight into HEAT and Its Extensions
J. Chem. Phys. 155, 184109 (2021) [DOI: 10.1063/5.0069322]
7   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]
8   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 [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.