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

This version of ATcT results was generated from an expansion of version 1.122o [4] to include an updated enthalpy of formation for Hydrazine. [5].

Species Name Formula Image    ΔfH°(0 K)    ΔfH°(298.15 K) Uncertainty Units Relative
Molecular
Mass		 ATcT ID
MethaneCH4 (g)C-66.561-74.530± 0.055kJ/mol16.04246 ±
0.00085		74-82-8*0

Representative Geometry of CH4 (g)

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Top contributors to the provenance of ΔfH° of CH4 (g)

The 20 contributors listed below account only for 80.3% of the provenance of ΔfH° of CH4 (g).
A total of 108 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
62.71888.1 2 H2 (g) + C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
3.61887.4 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.61 ± 0.21 kJ/molDale 2002
2.4118.2 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
2.31887.6 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.44 ± 0.26 kJ/molGOMB Ref Calorimeter, Alexandrov 2002
1.31887.1 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(303.15 K) = -889.849 ± 0.350 kJ/molRossini 1931a, Rossini 1931b, Prosen 1945, Rossini 1940, note CH4
1.31887.5 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.43 ± 0.35 kJ/molAlexandrov 2002a, Alexandrov 2002
0.91900.13 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 289.11 ± 0.10 kcal/molFeller 2016, note unc2
0.81887.2 CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (cr,l) ΔrH°(298.15 K) = -890.699 ± 0.430 kJ/molPittam 1972, note CH4a
0.71939.1 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 109.26 ± 0.08 kcal/molFeller 2016, est unc, note unc2
0.51902.4 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 1209.50 ± 0.56 kJ/molHarding 2008
0.41810.2 CO (g) → C+ (g) + O (g) ΔrH°(0 K) = 22.3713 ± 0.0015 eVNg 2007
0.41882.12 CH4 (g) → C (g) + 4 H (g) ΔrH°(0 K) = 392.46 ± 0.15 kcal/molKarton 2007a
0.41901.11 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 289.08 ± 0.15 kcal/molKarton 2008
0.31902.2 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 1209.48 ± 0.70 kJ/molHarding 2008
0.21902.3 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 1209.48 ± 0.74 kJ/molHarding 2008
0.21902.1 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 1209.93 ± 0.75 kJ/molTajti 2004, est unc
0.21900.9 CH3 (g) → C (g) + 3 H (g) ΔrH°(0 K) = 1209.93 ± 0.75 kJ/molTajti 2004, est unc
0.21764.7 C (graphite) + O2 (g) → CO2 (g) ΔrH°(298.15 K) = -393.464 ± 0.024 kJ/molHawtin 1966, note CO2e
0.21938.8 CH3 (g) → CH2 (g, triplet) + H (g) ΔrH°(0 K) = 457.05 ± 0.56 kJ/molHarding 2008
0.22414.1 CH3OH (g) → CH3 (g) + OH (g) ΔrH°(0 K) = 90.12 ± 0.17 kcal/molNguyen 2015a

Top 10 species with enthalpies of formation correlated to the ΔfH° of CH4 (g)

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
97.4 Methylium[CH3]+ (g)[CH3+]1099.3361095.392± 0.056kJ/mol15.03397 ±
0.00083		14531-53-4*0
89.3 MethylCH3 (g)[CH3]149.867146.453± 0.059kJ/mol15.03452 ±
0.00083		2229-07-4*0
83.3 Methane cation[CH4]+ (g)[CH4+]1150.6691144.286± 0.065kJ/mol16.04191 ±
0.00085		20741-88-2*0
30.6 IodomethaneCH3I (g)CI24.5014.97± 0.18kJ/mol141.93899 ±
0.00083		74-88-4*0
30.6 Methyl iodide cation[CH3I]+ (g)C[I+]944.79935.39± 0.18kJ/mol141.93844 ±
0.00083		12538-72-6*0
28.3 BromomethaneCH3Br (g)CBr-20.86-36.26± 0.18kJ/mol94.9385 ±
0.0013		74-83-9*0
27.6 IodomethaneCH3I (l)CI-12.18± 0.20kJ/mol141.93899 ±
0.00083		74-88-4*590
27.3 Methyl bromide cation[CH3Br]+ (g)C[Br+]996.25981.34± 0.18kJ/mol94.9380 ±
0.0013		12538-70-4*0
26.7 BromomethaneCH3Br (l)CBr-56.58-59.60± 0.19kJ/mol94.9385 ±
0.0013		74-83-9*590
25.5 Carbon atomC (g)[C]711.397716.882± 0.047kJ/mol12.01070 ±
0.00080		7440-44-0*0

Most Influential reactions involving CH4 (g)

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
0.9881883.1 CH4 (g) → [CH4]+ (g) ΔrH°(0 K) = 101752.2 ± 3.0 cm-1Worner 2007, note unc
0.9591909.1 CH4 (g) → [CH3]+ (g) + H (g) ΔrH°(0 K) = 14.32271 ± 0.00013 eVChang 2017
0.7261885.3 [CH4]- (g) → CH4 (g) ΔrH°(0 K) = -0.997 ± 0.061 eVRuscic G4
0.6271888.1 2 H2 (g) + C (graphite) → CH4 (g) ΔrG°(1165 K) = 37.521 ± 0.068 kJ/molSmith 1946, note COf, 3rd Law
0.2804792.2 HCCH (g) + 2 CH3Br (g) → BrCCBr (g) + 2 CH4 (g) ΔrH°(0 K) = 2.34 ± 1.0 kcal/molRuscic G4
0.2774754.11 CH2CHF (g) + CH4 (g) → CH2CH2 (g) + CH3F (g) ΔrH°(0 K) = 8.36 ± 0.20 kcal/molKarton 2011
0.2584798.12 HCCF (g) + CH3F (g) → FCCF (g) + CH4 (g) ΔrH°(0 K) = 14.03 ± 0.20 kcal/molKarton 2011
0.2521895.5 [CH5]+ (g) + CO2 (g) → [HOCO]+ (g) + CH4 (g) ΔrG°(296 K) = 7.92 ± 0.20 kJ/molBohme 1973a, 3rd Law, note unc
0.2314792.1 HCCH (g) + 2 CH3Br (g) → BrCCBr (g) + 2 CH4 (g) ΔrH°(0 K) = 3.37 ± 1.1 kcal/molRuscic G3X
0.2291895.7 [CH5]+ (g) + CO2 (g) → [HOCO]+ (g) + CH4 (g) ΔrG°(296 K) = 7.82 ± 0.21 kJ/molHemsworth 1973, 3rd Law, note unc
0.2234797.12 HCCH (g) + CH3F (g) → HCCF (g) + CH4 (g) ΔrH°(0 K) = 8.81 ± 0.20 kcal/molKarton 2011
0.2122170.8 CH2NH2 (g) + CH4 (g) → CH3NH2 (g) + CH3 (g) ΔrH°(0 K) = 12.19 ± 0.20 kcal/molKarton 2011
0.2114598.4 CH4 (g) + CBr4 (g) → 2 CH2Br2 (g) ΔrH°(0 K) = -3.33 ± 1.0 kcal/molRuscic G4
0.2081895.6 [CH5]+ (g) + CO2 (g) → [HOCO]+ (g) + CH4 (g) ΔrG°(296 K) = 7.72 ± 0.22 kJ/molBohme 1973a, 3rd Law, note unc
0.1894719.11 CH3CH2F (g) + CH4 (g) → CH3F (g) + CH3CH3 (g) ΔrH°(0 K) = 6.78 ± 0.20 kcal/molKarton 2011
0.1884389.7 4 CH3F (g) → CF4 (g) + 3 CH4 (g) ΔrH°(0 K) = -218.8 ± 2.0 kJ/molKlopper 2010a, est unc
0.1821885.4 [CH4]- (g) → CH4 (g) ΔrH°(0 K) = -0.852 ± 0.092 (×1.325) eVRuscic CBS-n
0.1744598.3 CH4 (g) + CBr4 (g) → 2 CH2Br2 (g) ΔrH°(0 K) = -3.41 ± 1.1 kcal/molRuscic G3X
0.1724291.4 2 CCl3CCl3 (g) + 3 CH4 (g) → 3 CCl4 (g) + 2 CH3CH3 (g) ΔrH°(0 K) = 17.46 ± 1.50 kcal/molRuscic W1RO
0.1642338.9 FCN (g) + CH4 (g) → HCN (g) + CH3F (g) ΔrH°(0 K) = -40.3 ± 1.7 kJ/molKlopper 2010a
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. 1.122p of the Thermochemical Network (2020); available at ATcT.anl.gov
4   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)
5   D. Feller, D. H. Bross, and B. Ruscic,
Enthalpy of Formation of N2H4 (Hydrazine) Revisited.
J. Phys. Chem. A 121, 6187-6198 (2017) [DOI: 10.1021/acs.jpca.7b06017]
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.