Methane

Formula: CH₄
Molecular weight: 16.0425
IUPAC Standard InChI: InChI=1S/CH4/h1H4
IUPAC Standard InChIKey: VNWKTOKETHGBQD-UHFFFAOYSA-N
CAS Registry Number: 74-82-8
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript.
Other names: Marsh gas; Methyl hydride; CH4; Fire Damp; R 50; Biogas; R 50 (refrigerant)
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Other data available:
- Gas phase thermochemistry data
- Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 100, reactions 101 to 112
- Henry's Law data
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- Vibrational and/or electronic energy levels
- Fluid Properties
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Phase change data

Go To: Top, References, Notes

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
DH - Eugene S. Domalski and Elizabeth D. Hearing
AC - William E. Acree, Jr., James S. Chickos

Quantity	Value	Units	Method	Reference	Comment
T_boil	111. ± 2.	K	AVG	N/A	Average of 13 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
T_fus	85.7	K	N/A	Streng, 1971	Uncertainty assigned by TRC = 0.2 K; TRC
T_fus	90.6	K	N/A	Van't Zelfde, Omar, et al., 1968	Uncertainty assigned by TRC = 0.3 K; TRC
T_fus	91.2	K	N/A	Timmermans, 1935	Uncertainty assigned by TRC = 2. K; TRC
T_fus	90.6	K	N/A	Clusius, 1929	Uncertainty assigned by TRC = 0.2 K; TRC
T_fus	90.5	K	N/A	Eucken and Karwat, 1924	Uncertainty assigned by TRC = 0.2 K; TRC
Quantity	Value	Units	Method	Reference	Comment
T_triple	90.67 ± 0.03	K	AVG	N/A	Average of 25 out of 32 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
P_triple	0.1169 ± 0.0006	bar	AVG	N/A	Average of 20 out of 23 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
T_c	190.6 ± 0.3	K	AVG	N/A	Average of 19 out of 23 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
P_c	46.1 ± 0.3	bar	AVG	N/A	Average of 16 out of 21 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
V_c	0.09860	l/mol	N/A	Ambrose and Tsonopoulos, 1995
V_c	0.09852	l/mol	N/A	Younglove and Ely, 1987	TRC
V_c	0.100	l/mol	N/A	Terry, Lynch, et al., 1969	Uncertainty assigned by TRC = 0.001 l/mol; TRC
Quantity	Value	Units	Method	Reference	Comment
ρ_c	10.1 ± 0.2	mol/l	AVG	N/A	Average of 16 out of 17 values; Individual data points

Enthalpy of vaporization

Δ_vapH (kJ/mol)	Temperature (K)	Method	Reference	Comment
8.519	99.54	N/A	Vogt and Pitzer, 1976	P = 2.81 kPa Data from Frank and Clusius, 1937 and 39FRA/CLU.; DH
8.6	101.	N/A	Stock, Henning, et al., 2006	Based on data from 92. to 110. K. See also Boublik, Fried, et al., 1984.; AC
8.6	105.	A	Stephenson and Malanowski, 1987	Based on data from 90. to 120. K.; AC
8.4	134.	A	Stephenson and Malanowski, 1987	Based on data from 115. to 149. K.; AC
8.7	174.	A	Stephenson and Malanowski, 1987	Based on data from 148. to 189. K.; AC
8.17	111.7	N/A	Majer and Svoboda, 1985
8.6	112.	N/A	Ott, Goates, et al., 1972	Based on data from 91. to 127. K. See also Boublik, Fried, et al., 1984.; AC
8.5	175.	N/A	Ott, Goates, et al., 1972	Based on data from 91. to 190. K.; AC
8.1	137.	N/A	Reid, 1972	AC
8.6	175.	N/A	Ambrose, Counsell, et al., 1970	Based on data from 100. to 190. K.; AC
8.2	112.	C	Hestermans and White, 1961	AC
7.5	130.	C	Hestermans and White, 1961	AC
5.9	160.	C	Hestermans and White, 1961	AC
4.0	180.	C	Hestermans and White, 1961	AC
8.5	149.	N/A	Hestermans and White, 1961	Based on data from 109. to 189. K.; AC
8.5 ± 0.1	99.	N/A	Frank and Clusius, 1939	AC

Enthalpy of vaporization

Δ_vapH = A exp(-αT_r) (1 − T_r)^β
Δ_vapH = Enthalpy of vaporization (at saturation pressure) (kJ/mol)
T_r = reduced temperature (T / T_c)

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Temperature (K)	112. to 180.
A (kJ/mol)	10.11
α	-0.22
β	0.388
T_c (K)	190.6
Reference	Majer and Svoboda, 1985

Entropy of vaporization

Δ_vapS (J/mol*K)	Temperature (K)	Reference	Comment
85.58	99.54	Vogt and Pitzer, 1976	P; DH

Antoine Equation Parameters

log₁₀(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)

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Temperature (K)	A	B	C	Reference	Comment
90.99 to 189.99	3.9895	443.028	-0.49	Prydz and Goodwin, 1972	Coefficents calculated by NIST from author's data.
96.89 to 110.19	2.00253	125.819	-48.823	Regnier, 1972	Coefficents calculated by NIST from author's data.
93.04 to 107.84	3.80235	403.106	-5.479	Cutler and Morrison, 1965	Coefficents calculated by NIST from author's data.
110.00 to 190.5	4.22061	516.689	11.223	Hestermans and White, 1961	Coefficents calculated by NIST from author's data.

Enthalpy of sublimation

Δ_subH (kJ/mol)	Temperature (K)	Method	Reference	Comment
9.7	72.	N/A	Stephenson and Malanowski, 1987	Based on data from 53. to 91. K.; AC
9.2	72.	N/A	Bondi, 1963	Based on data from 54. to 90. K. See also Armstrong, Brickwedde, et al., 1955.; AC
10.0	84.	N/A	Jones, 1960	Based on data from 79. to 89. K.; AC
9.7	63.	A,MS	Tickner and Lossing, 1951	Based on data from 48. to 78. K.; AC
9.62	77.	A	Stull, 1947	Based on data from 67. to 88. K.; AC

Enthalpy of phase transition

ΔH_trs (kJ/mol)	Temperature (K)	Initial Phase	Final Phase	Reference	Comment
0.09355	20.53	crystaline, II	crystaline, I	Vogt and Pitzer, 1976	Lambda transition.; DH
0.9392	90.67	crystaline, I	liquid	Vogt and Pitzer, 1976	DH

Entropy of phase transition

ΔS_trs (J/mol*K)	Temperature (K)	Initial Phase	Final Phase	Reference	Comment
4.557	20.53	crystaline, II	crystaline, I	Vogt and Pitzer, 1976	Lambda; DH
10.36	90.67	crystaline, I	liquid	Vogt and Pitzer, 1976	DH

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:

References

Go To: Top, Phase change data, Notes

Streng, 1971
Streng, A.G., Miscibility and Compatibility of Some Liquid and Solidified Gases at Low Temperature, J. Chem. Eng. Data, 1971, 16, 357. [all data]

Van't Zelfde, Omar, et al., 1968
Van't Zelfde, P.; Omar, M.H.; LePair-Schroten, H.G.M.; Dokoupil, Z., Solid-liquid equilibrium diagram for the argon + methane system., Physica (Amsterdam), 1968, 38, 241-51. [all data]

Timmermans, 1935
Timmermans, J., Researches in Stoichiometry. I. The Heat of Fusion of Organic Compounds., Bull. Soc. Chim. Belg., 1935, 44, 17-40. [all data]

Clusius, 1929
Clusius, K., The specific heat of several condensed gases between 10deg. abs. and their triple point., Z. Phys. Chem., Abt. B, 1929, 3, 41. [all data]

Eucken and Karwat, 1924
Eucken, A.; Karwat, E., Determination of the heat content of several condensed gases, Z. Phys. Chem., Stoechiom. Verwandtschaftsl., 1924, 112, 467. [all data]

Ambrose and Tsonopoulos, 1995
Ambrose, D.; Tsonopoulos, C., Vapor-Liquid Critical Properties of Elements and Compounds. 2. Normal Alkenes, J. Chem. Eng. Data, 1995, 40, 531-546. [all data]

Younglove and Ely, 1987
Younglove, B.A.; Ely, J.F., Thermophysical Properties of Fluids II. Methane, Ethane, Propane, Isobutane, and Normal Butane, J. Phys. Chem. Ref. Data, 1987, 16, 577. [all data]

Terry, Lynch, et al., 1969
Terry, M.J.; Lynch, J.T.; Bunclark, M.; Mansell, K.R.; Staveley, L.A.K., The Densities of Liquid Argon, Krypton, Xenon, Oxygen, Nitrogen, Carbon Monoxide, Methane and Carbon Tetrafluoride Along the Orthobaric Liquid Curve, J. Chem. Thermodyn., 1969, 1, 413. [all data]

Vogt and Pitzer, 1976
Vogt, G.J.; Pitzer, K.S., Entropy and heat capacity of methane, spin-species conversion, J. Chem. Thermodynam., 1976, 8, 1011-1031. [all data]

Frank and Clusius, 1937
Frank, A.; Clusius, K., The entropy of methane, Z. Physik. Chem., 1937, B36, 291-300. [all data]

Stock, Henning, et al., 2006
Stock, Alfred; Henning, Fritz; Kuß, Ernst, Dampfdrucktafeln für Temperaturbestimmungen zwischen + 25° und - 185°, Ber. dtsch. Chem. Ges. A/B, 2006, 54, 5, 1119-1129, https://doi.org/10.1002/cber.19210540531 . [all data]

Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E., The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Majer and Svoboda, 1985
Majer, V.; Svoboda, V., Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]

Ott, Goates, et al., 1972
Ott, J. Bevan; Goates, J. Rex; Lamb, John D., Solid-liquid phase equilibria in water + ethylene glycol, The Journal of Chemical Thermodynamics, 1972, 4, 1, 123-126, https://doi.org/10.1016/S0021-9614(72)80015-6 . [all data]

Reid, 1972
Reid, Robert C., Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00, AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637 . [all data]

Ambrose, Counsell, et al., 1970
Ambrose, D.; Counsell, J.F.; Davenport, A.J., The use of Chebyshev polynomials for the representation of vapour pressures between the triple point and the critical point, The Journal of Chemical Thermodynamics, 1970, 2, 2, 283-294, https://doi.org/10.1016/0021-9614(70)90093-5 . [all data]

Hestermans and White, 1961
Hestermans, P.; White, David, THE VAPOR PRESSURE, HEAT OF VAPORIZATION AND HEAT CAPACITY OF METHANE FROM THE BOILING POINT TO THE CRITICAL TEMPERATURE, J. Phys. Chem., 1961, 65, 2, 362-365, https://doi.org/10.1021/j100820a044 . [all data]

Frank and Clusius, 1939
Frank, A.; Clusius, K., Z. Phys. Chem. Abt. B, 1939, 42, 395. [all data]

Prydz and Goodwin, 1972
Prydz, R.; Goodwin, R.D., Experimental Melting and Vapor Pressures of Methane, J. Chem. Thermodyn., 1972, 4, 1, 127-133, https://doi.org/10.1016/S0021-9614(72)80016-8 . [all data]

Regnier, 1972
Regnier, J., Tension de Vapeur de L'Ethane Entre 80 et 135 K, J. Chim. Phys., 1972, 69, 942-944. [all data]

Cutler and Morrison, 1965
Cutler, A.J.B.; Morrison, J.A., Excess Thermodynamic Functions for Liquid Mixtures of Methane+Propane, Trans. Faraday Soc., 1965, 61, 429-442, https://doi.org/10.1039/tf9656100429 . [all data]

Bondi, 1963
Bondi, A., Heat of Siblimation of Molecular Crystals: A Catalog of Molecular Structure Increments., J. Chem. Eng. Data, 1963, 8, 3, 371-381, https://doi.org/10.1021/je60018a027 . [all data]

Armstrong, Brickwedde, et al., 1955
Armstrong, George T.; Brickwedde, F.G.; Scott, R.B., Vapor pressures of the methanes, J. RES. NATL. BUR. STAN., 1955, 55, 1, 39, https://doi.org/10.6028/jres.055.005 . [all data]

Jones, 1960
Jones, A.H., Sublimation Pressure Data for Organic Compounds., J. Chem. Eng. Data, 1960, 5, 2, 196-200, https://doi.org/10.1021/je60006a019 . [all data]

Tickner and Lossing, 1951
Tickner, A.W.; Lossing, F.P., The Measurement of Low Vapor Pressures by Means of a Mass Spectrometer., J. Phys. Chem., 1951, 55, 5, 733-740, https://doi.org/10.1021/j150488a013 . [all data]

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

Notes

Go To: Top, Phase change data, References

Symbols used in this document:

P_c	Critical pressure
P_triple	Triple point pressure
T_boil	Boiling point
T_c	Critical temperature
T_fus	Fusion (melting) point
T_triple	Triple point temperature
V_c	Critical volume
ΔH_trs	Enthalpy of phase transition
ΔS_trs	Entropy of phase transition
Δ_subH	Enthalpy of sublimation
Δ_vapH	Enthalpy of vaporization
Δ_vapS	Entropy of vaporization
ρ_c	Critical density

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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