Methane
- Formula: CH4
- Molecular weight: 16.0425
- 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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Gas phase thermochemistry data
Go To: Top, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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 |
---|---|---|---|---|---|
ΔfH°gas | -17.89 | kcal/mol | Review | Chase, 1998 | Data last reviewed in March, 1961 |
ΔfH°gas | -17.8 ± 0.07 | kcal/mol | Review | Manion, 2002 | adopted recommendation of Gurvich, Veyts, et al., 1991; DRB |
ΔfH°gas | -17.8 ± 0.1 | kcal/mol | Ccb | Pittam and Pilcher, 1972 | ALS |
ΔfH°gas | -17.889 ± 0.075 | kcal/mol | Ccb | Prosen and Rossini, 1945 | Hf derived from Heat of Hydrogenation; ALS |
ΔfH°gas | -17.54 ± 0.26 | kcal/mol | Ccb | Roth and Banse, 1932 | Reanalyzed by Cox and Pilcher, 1970, Original value = -17.97 kcal/mol; ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°gas | -212.88 ± 0.09 | kcal/mol | Ccb | Pittam and Pilcher, 1972 | Corresponding ΔfHºgas = -17.80 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°gas | -212.798 ± 0.072 | kcal/mol | Ccb | Prosen and Rossini, 1945 | Hf derived from Heat of Hydrogenation; Corresponding ΔfHºgas = -17.883 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°gas | -213.14 ± 0.26 | kcal/mol | Ccb | Roth and Banse, 1932 | Reanalyzed by Cox and Pilcher, 1970, Original value = -212.07 ± 0.25 kcal/mol; Corresponding ΔfHºgas = -17.54 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°gas | -212.753 ± 0.072 | kcal/mol | Cm | Rossini, 1931 | Corresponding ΔfHºgas = -17.928 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°gas | 45.09 ± 0.10 | cal/mol*K | N/A | Colwell J.H., 1963 | The calorimetric value is significantly higher than the statistically calculated entropy, 186.26 J/mol*K, 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/mol*K 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 | 44.515 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in March, 1961 |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
8.346 ± 0.060 | 279. | Halford J.O., 1957 | GT |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
7.954 | 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 |
8.009 | 200. | ||
8.530 | 298.15 | ||
8.547 | 300. | ||
9.711 | 400. | ||
11.14 | 500. | ||
12.61 | 600. | ||
14.01 | 700. | ||
15.32 | 800. | ||
16.52 | 900. | ||
17.63 | 1000. | ||
18.62 | 1100. | ||
19.52 | 1200. | ||
20.33 | 1300. | ||
21.06 | 1400. | ||
21.72 | 1500. | ||
22.31 | 1600. | ||
22.84 | 1700. | ||
23.33 | 1800. | ||
23.78 | 1900. | ||
24.197 | 2000. | ||
24.577 | 2100. | ||
24.931 | 2200. | ||
25.263 | 2300. | ||
25.574 | 2400. | ||
25.868 | 2500. | ||
26.145 | 2600. | ||
26.410 | 2700. | ||
26.663 | 2800. | ||
26.905 | 2900. | ||
27.139 | 3000. |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = 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
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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Temperature (K) | 298. to 1300. | 1300. to 6000. |
---|---|---|
A | -0.168028 | 20.50960 |
B | 25.92670 | 2.692321 |
C | -10.16290 | -0.505293 |
D | 1.401240 | 0.033028 |
E | 0.162181 | -6.315060 |
F | -18.36610 | -36.69520 |
G | 37.93411 | 53.63631 |
H | -17.89510 | -17.89510 |
Reference | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in March, 1961 | Data last reviewed in March, 1961 |
References
Go To: Top, Gas phase thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
Notes
Go To: Top, Gas phase thermochemistry data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas S°gas Entropy of gas at standard conditions S°gas,1 bar Entropy of gas at standard conditions (1 bar) ΔcH°gas Enthalpy of combustion of gas at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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