Butane, 2-methyl-
- Formula: C5H12
- Molecular weight: 72.1488
- IUPAC Standard InChI: InChI=1S/C5H12/c1-4-5(2)3/h5H,4H2,1-3H3
- IUPAC Standard InChIKey: QWTDNUCVQCZILF-UHFFFAOYSA-N
- CAS Registry Number: 78-78-4
- 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: iso-Pentane; 1,1,2-Trimethylethane; 2-Methylbutane; iso-C5H12; Ethyldimethylmethane; Isoamylhydride; Exxsol isopentane S; 1,1-Dimethylpropane; Methylbutane; NSC 119476
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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:
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 | -153.7 ± 0.59 | kJ/mol | Ccb | Good, 1970 | ALS |
| ΔfH°gas | -154.1 ± 0.96 | kJ/mol | Cm | Pilcher and Chadwick, 1967 | ALS |
| ΔfH°gas | -154.5 ± 0.84 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°gas | -3528.4 ± 0.92 | kJ/mol | Cm | Pilcher and Chadwick, 1967 | Corresponding ΔfHºgas = -154.1 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
| ΔcH°gas | -3528.6 ± 0.63 | kJ/mol | Cm | Knowlton and Rossini, 1939 | Corresponding ΔfHºgas = -153.9 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
| ΔcH°gas | -3527.6 ± 3.5 | kJ/mol | Ccb | Roth and Pahlke, 1936 | Reanalyzed by Cox and Pilcher, 1970, Original value = -3529.0 kJ/mol; Corresponding ΔfHºgas = -155.0 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Constant pressure heat capacity of gas
| Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 84.94 | 200. | Scott D.W., 1974 | Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, 2, Scott D.W., 1974]. This approach gives a better agreement with experimental data than the statistical thermodynamics calculations [ Pitzer K.S., 1946, Scott D.W., 1951].; GT |
| 110.37 | 273.15 | ||
| 118.9 ± 0.4 | 298.15 | ||
| 119.50 | 300. | ||
| 152.88 | 400. | ||
| 183.26 | 500. | ||
| 210.04 | 600. | ||
| 233.05 | 700. | ||
| 253.13 | 800. | ||
| 270.70 | 900. | ||
| 286.19 | 1000. | ||
| 299.57 | 1100. | ||
| 311.29 | 1200. | ||
| 322.17 | 1300. | ||
| 330.54 | 1400. | ||
| 338.90 | 1500. |
Constant pressure heat capacity of gas
| Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 125.31 ± 0.37 | 317.20 | Scott D.W., 1951 | GT |
| 139.12 ± 0.42 | 358.15 | ||
| 153.64 ± 0.46 | 402.30 | ||
| 168.36 ± 0.51 | 449.20 | ||
| 179.62 ± 0.54 | 487.05 |
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.
Good, 1970
Good, W.D.,
The enthalpies of combustion and formation of the isomeric pentanes,
J. Chem. Thermodyn., 1970, 2, 237-244. [all data]
Pilcher and Chadwick, 1967
Pilcher, G.; Chadwick, J.D.M.,
Measurements of heats of combustion by flame calorimetry. Part 4.-n-Pentane, isopentane, neopentane,
Trans. Faraday Soc., 1967, 63, 2357-2361. [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]
Knowlton and Rossini, 1939
Knowlton, J.W.; Rossini, F.D.,
Heats of combustion of tetramethylmethane and 2-methylbutane,
J. Res. NBS, 1939, 22, 415-424. [all data]
Roth and Pahlke, 1936
Roth, W.A.; Pahlke, H.,
Sekundare eichsubstanz fur verbrennungscalorimeter fur gase und dampfe. Die verbrennungswarme von isopentandampf,
Angew. Chem., 1936, 49, 618-619. [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]
Scott D.W., 1974
Scott D.W.,
Chemical Thermodynamic Properties of Hydrocarbons and Related Substances. Properties of the Alkane Hydrocarbons, C1 through C10 in the Ideal Gas State from 0 to 1500 K. U.S. Bureau of Mines, Bulletin 666, 1974. [all data]
Scott D.W., 1974, 2
Scott D.W.,
Correlation of the chemical thermodynamic properties of alkane hydrocarbons,
J. Chem. Phys., 1974, 60, 3144-3165. [all data]
Pitzer K.S., 1946
Pitzer K.S.,
The entropies and related properties of branched paraffin hydrocarbons,
Chem. Rev., 1946, 39, 435-447. [all data]
Scott D.W., 1951
Scott D.W.,
Rotational isomerism and thermodynamic functions of 2-methylbutane and 2,3-dimethylbutane. Vapor heat capacity and heat of vaporization of 2-methylbutane,
J. Am. Chem. Soc., 1951, 73, 1707-1712. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas 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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