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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Information on this page:
Other data available:
- Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 100, reactions 101 to 112
- Henry's Law data
- Ion clustering data
- IR Spectrum
- Vibrational and/or electronic energy levels
- Fluid Properties
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Gas phase thermochemistry data

Go To: Top, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References, Notes

Data compiled as indicated in comments:
DRB - Donald R. Burgess, Jr.
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Quantity	Value	Units	Method	Reference	Comment
Δ_fH°_gas	-74.87	kJ/mol	Review	Chase, 1998	Data last reviewed in March, 1961
Δ_fH°_gas	-74.6 ± 0.3	kJ/mol	Review	Manion, 2002	adopted recommendation of Gurvich, Veyts, et al., 1991; DRB
Δ_fH°_gas	-74.5 ± 0.4	kJ/mol	Ccb	Pittam and Pilcher, 1972	ALS
Δ_fH°_gas	-74.85 ± 0.31	kJ/mol	Ccb	Prosen and Rossini, 1945	Hf derived from Heat of Hydrogenation; ALS
Δ_fH°_gas	-73.4 ± 1.1	kJ/mol	Ccb	Roth and Banse, 1932	Reanalyzed by Cox and Pilcher, 1970, Original value = -75.19 kJ/mol; ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_gas	-890.7 ± 0.4	kJ/mol	Ccb	Pittam and Pilcher, 1972	Corresponding Δ_fHº_gas = -74.48 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_gas	-890.35 ± 0.30	kJ/mol	Ccb	Prosen and Rossini, 1945	Hf derived from Heat of Hydrogenation; Corresponding Δ_fHº_gas = -74.822 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_gas	-891.8 ± 1.1	kJ/mol	Ccb	Roth and Banse, 1932	Reanalyzed by Cox and Pilcher, 1970, Original value = -887.3 ± 1.0 kJ/mol; Corresponding Δ_fHº_gas = -73.39 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_gas	-890.16 ± 0.30	kJ/mol	Cm	Rossini, 1931	Corresponding Δ_fHº_gas = -75.010 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_gas	188.66 ± 0.42	J/mol*K	N/A	Colwell J.H., 1963	The calorimetric value is significantly higher than the statistically calculated entropy, 186.26 J/molK, which remains the best value for use in thermodynamic calculations [ Vogt G.J., 1976, Friend D.G., 1989, Gurvich, Veyts, et al., 1989]. Earlier the value of 185.3 J/molK was calculated from experimental data [ Giauque W.F., 1931]. The value of S(298.15 K)=185.94 J/mol*K was obtained by high accuracy ab initio calculation [ East A.L.L., 1997].; GT
Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	186.25	J/mol*K	Review	Chase, 1998	Data last reviewed in March, 1961

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
34.92 ± 0.25	279.	Halford J.O., 1957	GT

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
33.28	100.	Gurvich, Veyts, et al., 1989	p=1 bar. Because of more precise method of calculation, the recommended values are more accurate, especially at high temperatures, than those obtained by [ McDowell R.S., 1963] and often regarded as reference data [ Friend D.G., 1989].; GT
33.51	200.
35.69	298.15
35.76	300.
40.63	400.
46.63	500.
52.74	600.
58.60	700.
64.08	800.
69.14	900.
73.75	1000.
77.92	1100.
81.68	1200.
85.07	1300.
88.11	1400.
90.86	1500.
93.33	1600.
95.58	1700.
97.63	1800.
99.51	1900.
101.24	2000.
102.83	2100.
104.31	2200.
105.70	2300.
107.00	2400.
108.23	2500.
109.39	2600.
110.50	2700.
111.56	2800.
112.57	2900.
113.55	3000.

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
C_p = heat capacity (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.

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View table.

Temperature (K)	298. to 1300.	1300. to 6000.
A	-0.703029	85.81217
B	108.4773	11.26467
C	-42.52157	-2.114146
D	5.862788	0.138190
E	0.678565	-26.42221
F	-76.84376	-153.5327
G	158.7163	224.4143
H	-74.87310	-74.87310
Reference	Chase, 1998	Chase, 1998
Comment	Data last reviewed in March, 1961	Data last reviewed in March, 1961

Phase change data

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, Mass spectrum (electron ionization), 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:

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), References, Notes

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

View reactions leading to CH₄⁺ (ion structure unspecified)

Quantity	Value	Units	Method	Reference	Comment
IE (evaluated)	12.61 ± 0.01	eV	N/A	N/A	L
Quantity	Value	Units	Method	Reference	Comment
Proton affinity (review)	543.5	kJ/mol	N/A	Hunter and Lias, 1998	HL
Quantity	Value	Units	Method	Reference	Comment
Gas basicity	520.6	kJ/mol	N/A	Hunter and Lias, 1998	HL

Ionization energy determinations

IE (eV)	Method	Reference	Comment
12.61 ± 0.01	PI	Berkowitz, Greene, et al., 1987	LBLHLM
12.6 ± 0.4	EI	Chatham, Hils, et al., 1984	LBLHLM
12.63 ± 0.02	EI	Plessis, Marmet, et al., 1983	LBLHLM
13.6	PE	Kimura, Katsumata, et al., 1981	LLK
12.75 ± 0.02	PE	Bieri, Burger, et al., 1977	LLK
12.82 ± 0.02	EI	Selim and El-Kholy, 1975	LLK
12.6	PE	Debies and Rabalais, 1975	LLK
12.6	PI	Rabalais, Debies, et al., 1974	LLK
12.8	EI	Morrison and Traeger, 1973	LLK
12.64	PE	Potts and Price, 1972	LLK
12.94 ± 0.04	EI	Finney and Harrison, 1972	LLK
12.51	PE	Bergmark, Rabalais, et al., 1972	LLK
~12.51	PE	Rabalais, Bergmark, et al., 1971	LLK
≤12.615 ± 0.010	PI	Chupka and Berkowitz, 1971	LLK
12.78	PE	Pullen, Carlson, et al., 1970	RDSH
12.75	PE	Brundle, Robin, et al., 1970	RDSH
≤12.70	EI	Lossing and Semeluk, 1969	RDSH
12.99 ± 0.05	EI	Williams and Hamill, 1968	RDSH
12.75 ± 0.05	TE	Villarejo, Stockbauer, et al., 1968	RDSH
12.9	CI	Cermak, 1968	RDSH
12.70	PE	Baker, Baker, et al., 1968	RDSH
12.55 ± 0.05	PI	Brehm, 1966	RDSH
12.704 ± 0.008	PI	Nicholson, 1965	RDSH
12.71 ± 0.02	PI	Dibeler, Krauss, et al., 1965	RDSH
13.00 ± 0.02	EI	Melton and Hamill, 1964	RDSH
13.6	PE	Bieri and Asbrink, 1980	Vertical value; LLK
13.6 ± 0.1	PE	Bieri, Burger, et al., 1977	Vertical value; LLK
13.60	EI	Harshbarger, Robin, et al., 1973	Vertical value; LLK

Appearance energy determinations

Ion	AE (eV)	Other Products	Method	Reference	Comment
C⁺	25. ± 2.	?	EI	Chatham, Hils, et al., 1984	LBLHLM
C⁺	19.56 ± 0.20	2H₂	EI	Plessis, Marmet, et al., 1983	LBLHLM
C⁺	≤25.2	?	EI	Morrison and Traeger, 1973	LLK
CH⁺	22.2 ± 0.4	?	EI	Chatham, Hils, et al., 1984	LBLHLM
CH⁺	19.11 ± 0.20	H^-+H₂	EI	Plessis, Marmet, et al., 1983	LBLHLM
CH⁺	19.87 ± 0.20	H+H₂	EI	Plessis, Marmet, et al., 1983	LBLHLM
CH⁺	22.4	H₂+H?	EI	Morrison and Traeger, 1973	LLK
CH₂⁺	15.1 ± 0.4	H₂	EI	Chatham, Hils, et al., 1984	LBLHLM
CH₂⁺	15.06 ± 0.02	H₂	EI	Plessis, Marmet, et al., 1983	LBLHLM
CH₂⁺	15.16 ± 0.02	H₂	PI	McCulloh and Dibeler, 1976	T = 0K; LLK
CH₂⁺	15.3	H₂	EI	Morrison and Traeger, 1973	LLK
CH₂⁺	15.19 ± 0.02	H₂	PI	Chupka, 1968	RDSH
CH₂⁺	15.16 ± 0.04	H₂	PI	Dibeler, Krauss, et al., 1965	RDSH
CH₃⁺	14.3 ± 0.4	H	EI	Chatham, Hils, et al., 1984	LBLHLM
CH₃⁺	13.25 ± 0.08	H^-	EI	Plessis, Marmet, et al., 1983	LBLHLM
CH₃⁺	14.01 ± 0.08	H	EI	Plessis, Marmet, et al., 1983	LBLHLM
CH₃⁺	14.30	H	PIPECO	Stockbauer, 1977	LLK
CH₃⁺	14.324 ± 0.003	H	PI	McCulloh and Dibeler, 1976	T = 0K; LLK
CH₃⁺	14.4	H	EI	Morrison and Traeger, 1973	LLK
CH₃⁺	14.30	H	EI	Lossing and Semeluk, 1970	RDSH
CH₃⁺	14.24 ± 0.05	H	EI	Williams and Hamill, 1968	RDSH
CH₃⁺	13.50 ± 0.05	H^-	PI	Chupka, 1968	RDSH
CH₃⁺	14.320 ± 0.004	H	PI	Chupka, 1968	RDSH
CH₃⁺	14.23 ± 0.05	H	PI	Brehm, 1966	RDSH
CH₃⁺	14.25 ± 0.02	H	PI	Dibeler, Krauss, et al., 1965	RDSH
H⁺	21.3 ± 0.3	CH₃	EI	Locht, Olivier, et al., 1979	LLK
H⁺	24.0 ± 0.5	CH₃	EI	Appell and Kubach, 1971	LLK

De-protonation reactions

CH₃^- + = Methane

By formula: CH₃^- + H⁺ = CH₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1743.6 ± 2.9	kJ/mol	D-EA	Ellison, Engelking, et al., 1978	gas phase; B
Δ_rH°	1749. ± 15.	kJ/mol	CIDT	Graul and Squires, 1990	gas phase; B
Δ_rH°	>1691.1 ± 0.42	kJ/mol	G+TS	Bohme, Lee-Ruff, et al., 1972	gas phase; B
Δ_rH°	1735.5	kJ/mol	N/A	Check, Faust, et al., 2001	gas phase; FeBr3; ; ΔS(EA)=9.3; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1709.8 ± 3.3	kJ/mol	H-TS	Ellison, Engelking, et al., 1978	gas phase; B
Δ_rG°	1715. ± 15.	kJ/mol	H-TS	Graul and Squires, 1990	gas phase; B
Δ_rG°	>1657.3	kJ/mol	IMRB	Bohme, Lee-Ruff, et al., 1972	gas phase; B
Δ_rG°	1704.1	kJ/mol	N/A	Check, Faust, et al., 2001	gas phase; FeBr3; ; ΔS(EA)=9.3; B

Mass spectrum (electron ionization)

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, References, Notes

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

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Owner	NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.
Origin	D.HENNEBERG, MAX-PLANCK INSTITUTE, MULHEIM, WEST GERMANY
NIST MS number	61313

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References

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), Notes

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Manion, 2002
Manion, J.A., Evaluated Enthalpies of Formation of the Stable Closed Shell C1 and C2 Chlorinated Hydrocarbons, J. Phys. Chem. Ref. Data, 2002, 31, 1, 123-172, https://doi.org/10.1063/1.1420703 . [all data]

Gurvich, Veyts, et al., 1991
Thermodynamic Properties of Individual Substances, 4th edition, Volume 2, Gurvich, L.V.; Veyts, I.V.; Alcock, C.B.;, ed(s)., Hemisphere, New York, 1991. [all data]

Pittam and Pilcher, 1972
Pittam, D.A.; Pilcher, G., Measurements of heats of combustion by flame calorimetry. Part 8.-Methane, ethane, propane, n-butane and 2-methylpropane, J. Chem. Soc. Faraday Trans. 1, 1972, 68, 2224-2229. [all data]

Prosen and Rossini, 1945
Prosen, E.J.; Rossini, F.D., Heats of combustion and formation of the paraffin hydrocarbons at 25° C, J. Res. NBS, 1945, 263-267. [all data]

Roth and Banse, 1932
Roth, W.A.; Banse, H., Die verbrennungs- und bildungswarme von kohlenoxyd und methan, Arch. Eisenhutten., 1932, 6, 43-46. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Rossini, 1931
Rossini, F.D., The heats of combustion of methane and carbon monoxide, J. Res. NBS, 1931, 6, 37-49. [all data]

Colwell J.H., 1963
Colwell J.H., Thermodynamic properties of CH4 and CD4. Interpretation of the properties of solid, J. Chem. Phys., 1963, 39, 635-653. [all data]

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

Friend D.G., 1989
Friend D.G., Thermophysical properties of methane, J. Phys. Chem. Ref. Data, 1989, 18, 583-638. [all data]

Gurvich, Veyts, et al., 1989
Gurvich, L.V.; Veyts, I.V.; Alcock, C.B., Thermodynamic Properties of Individual Substances, 4th ed.; Vols. 1 and 2, Hemisphere, New York, 1989. [all data]

Giauque W.F., 1931
Giauque W.F., The entropies of methane and ammonia, Phys. Rev., 1931, 38, 196-197. [all data]

East A.L.L., 1997
East A.L.L., Ab initio statistical thermodynamical models for the computation of third-law entropies, J. Chem. Phys., 1997, 106, 6655-6674. [all data]

Halford J.O., 1957
Halford J.O., Standard heat capacities of gaseous methanol, ethanol, methane and ethane at 279 K by thermal conductivity, J. Phys. Chem., 1957, 61, 1536-1539. [all data]

McDowell R.S., 1963
McDowell R.S., Thermodynamic functions of methane, J. Chem. Eng. Data, 1963, 8, 547-548. [all data]

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
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Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

Symbols used in this document:

AE	Appearance energy
C_p,gas	Constant pressure heat capacity of gas
IE (evaluated)	Recommended ionization energy
P_c	Critical pressure
P_triple	Triple point pressure
S°_gas	Entropy of gas at standard conditions
S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
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_cH°_gas	Enthalpy of combustion of gas at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
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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NIST Chemistry WebBook, SRD 69

Methane

Data at NIST subscription sites:

Gas phase thermochemistry data

Constant pressure heat capacity of gas

Constant pressure heat capacity of gas

Gas Phase Heat Capacity (Shomate Equation)

Phase change data

Enthalpy of vaporization

Enthalpy of vaporization

Entropy of vaporization

Antoine Equation Parameters

Enthalpy of sublimation

Enthalpy of phase transition

Entropy of phase transition

Gas phase ion energetics data

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

Mass spectrum (electron ionization)

Spectrum

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