Pentane, 2-methyl-

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Gas phase thermochemistry data

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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
Δfgas-41.66 ± 0.25kcal/molCcbProsen and Rossini, 1945ALS
Quantity Value Units Method Reference Comment
Δcgas-993.71 ± 0.23kcal/molCcbProsen and Rossini, 1945Corresponding Δfgas = -48.80 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS

Constant pressure heat capacity of gas

Cp,gas (cal/mol*K) Temperature (K) Reference Comment
24.221200.Scott D.W., 1974Recommended 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 calculation [ Pitzer K.S., 1946] (see also [ Waddington G., 1949]).; GT
31.520273.15
33.99 ± 0.05298.15
34.180300.
43.860400.
52.541500.
60.000600.
66.300700.
71.800800.
76.501900.
80.6001000.
84.0991100.
87.1991200.
90.0001300.
93.0001400.
95.0001500.

Constant pressure heat capacity of gas

Cp,gas (cal/mol*K) Temperature (K) Reference Comment
36.771325.10Waddington G., 1949GT
40.301362.15
44.080402.25
47.139436.20
50.160471.15

Phase change data

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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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
BS - Robert L. Brown and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tboil334. ± 1.KAVGN/AAverage of 71 out of 73 values; Individual data points
Quantity Value Units Method Reference Comment
Tfus120. ± 7.KAVGN/AAverage of 21 values; Individual data points
Quantity Value Units Method Reference Comment
Ttriple119.55KN/ADouslin and Huffman, 1946Uncertainty assigned by TRC = 0.07 K; TRC
Ttriple119.55KN/AHuffman, 1945Uncertainty assigned by TRC = 0.03 K; based on To = 273.16 K; TRC
Ttriple119.7KN/AStull, 1937Uncertainty assigned by TRC = 0.1 K; measured by Wojciechowski; TRC
Quantity Value Units Method Reference Comment
Tc497.8 ± 0.4KAVGN/AAverage of 10 values; Individual data points
Quantity Value Units Method Reference Comment
Pc29.95 ± 0.07atmAVGN/AAverage of 6 values; Individual data points
Quantity Value Units Method Reference Comment
Vc0.368l/molN/ADaubert, 1996 
Quantity Value Units Method Reference Comment
ρc2.72 ± 0.02mol/lN/ADaubert, 1996 
ρc2.734mol/lN/AHolcomb, Magee, et al., 1995Uncertainty assigned by TRC = 0.05 mol/l; TRC
ρc2.72mol/lN/AGenco, Teja, et al., 1980Uncertainty assigned by TRC = 0.06 mol/l; TRC
ρc2.73mol/lN/AKay, 1946Uncertainty assigned by TRC = 0.02 mol/l; by extrapolation of rectilinear diameter to Tc; TRC
Quantity Value Units Method Reference Comment
Δvap7.0 ± 0.9kcal/molAVGN/AAverage of 6 values; Individual data points

Enthalpy of vaporization

ΔvapH (kcal/mol) Temperature (K) Method Reference Comment
6.642333.4N/AMajer and Svoboda, 1985 
7.22305.N/ASapei, Uusi-Kyyny, et al., 2010Based on data from 290. to 333. K.; AC
7.17316.N/APokki, Uusi-Kyyny, et al., 2002Based on data from 301. to 333. K.; AC
7.10325.N/AAucejo, Loras, et al., 1998Based on data from 310. to 359. K.; AC
7.29308.AStephenson and Malanowski, 1987Based on data from 293. to 335. K.; AC
6.86 ± 0.02318.CWaddington, Smith, et al., 1949AC
6.64 ± 0.02333.CWaddington, Smith, et al., 1949AC
7.27301.MMWillingham, Taylor, et al., 1945Based on data from 286. to 334. K.; AC
7.12 ± 0.05293.CLemons and Felsing, 1943AC
6.93 ± 0.05313.CLemons and Felsing, 1943AC
6.60 ± 0.05333.CLemons and Felsing, 1943AC
6.43 ± 0.05353.CLemons and Felsing, 1943AC

Enthalpy of vaporization

ΔvapH = A exp(-βTr) (1 − Tr)β
    ΔvapH = Enthalpy of vaporization (at saturation pressure) (kcal/mol)
    Tr = reduced temperature (T / Tc)

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Temperature (K) A (kcal/mol) β Tc (K) Reference Comment
298. to 333.10.820.2739497.5Majer and Svoboda, 1985 

Antoine Equation Parameters

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

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Temperature (K) A B C Reference
285.91 to 334.223.95831135.41-46.578Williamham, Taylor, et al., 1945

Enthalpy of fusion

ΔfusH (kcal/mol) Temperature (K) Reference Comment
1.498119.55Douslin and Huffman, 1946, 2DH
1.50119.6Domalski and Hearing, 1996AC

Entropy of fusion

ΔfusS (cal/mol*K) Temperature (K) Reference Comment
12.53119.55Douslin and Huffman, 1946, 2DH

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:


Henry's Law data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Rolf Sander

Henry's Law constant (water solution)

kH(T) = H exp(d(ln(kH))/d(1/T) ((1/T) - 1/(298.15 K)))
H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(kH))/d(1/T) = Temperature dependence constant (K)

H (mol/(kg*bar)) d(ln(kH))/d(1/T) (K) Method Reference Comment
0.00057 QN/A missing citation give several references for the Henry's law constants but don't assign them to specific species.
0.13960.XN/A 
0.00060 LN/A 
0.00058 VN/A 

Gas phase ion energetics data

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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:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

IE (eV) Method Reference Comment
10.04ESTLuo and Pacey, 1992LL
9.89 ± 0.15EQMautner(Meot-Ner), Sieck, et al., 1981LLK
10.12PIWatanabe, Nakayama, et al., 1962RDSH

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C3H6+10.91 ± 0.05C3H8PISteiner, Giese, et al., 1961RDSH
C3H7+~11.35 ± 0.10C3H7PISteiner, Giese, et al., 1961RDSH
C4H8+10.65 ± 0.015C2H6PISteiner, Giese, et al., 1961RDSH
C4H9+10.73 ± 0.02C2H5PISteiner, Giese, et al., 1961RDSH
C5H10+10.835 ± 0.025CH4PISteiner, Giese, et al., 1961RDSH
C5H11+10.865 ± 0.085CH3PISteiner, Giese, et al., 1961RDSH

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law data, Gas phase ion energetics data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

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]

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]

Waddington G., 1949
Waddington G., Experimental vapor heat capacities and heats of vaporization of 2-methylpentane, 3-methylpentane, and 2,3-dimethylbutane, J. Am. Chem. Soc., 1949, 71, 3902-3906. [all data]

Douslin and Huffman, 1946
Douslin, D.R.; Huffman, H.M., Low-Temperature Thermal Data on the Five Isomeric Hexanes, J. Am. Chem. Soc., 1946, 68, 1704. [all data]

Huffman, 1945
Huffman, H.M., Personal Commun., U. S. Bur. Mines, Bartlesville, OK, July 25, 1945. [all data]

Stull, 1937
Stull, D.R., A Semi-micro Calorimeter for Measuring Heat Capacities at Low Temp., J. Am. Chem. Soc., 1937, 59, 2726. [all data]

Daubert, 1996
Daubert, T.E., Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes, J. Chem. Eng. Data, 1996, 41, 365-372. [all data]

Holcomb, Magee, et al., 1995
Holcomb, C.D.; Magee, J.W.; Haynes, W.M., Density Measurements on Natural Gas Liquids, Research Report RR-147, Gas Processors Association Project 916, 1995. [all data]

Genco, Teja, et al., 1980
Genco, J.M.; Teja, A.S.; Kay, W.B., Study of the critical and azeotropic behavior of binary mixtures I critical states of perfluoromethylcyclohexane + isomeric hexane systems, J. Chem. Eng. Data, 1980, 25, 350. [all data]

Kay, 1946
Kay, W.B., The Vapor Pressures and Saturated Liquid and Vapor Densities of the Isomeric Hexanes, J. Am. Chem. Soc., 1946, 68, 1336. [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]

Sapei, Uusi-Kyyny, et al., 2010
Sapei, Erlin; Uusi-Kyyny, Petri; Keskinen, Kari I.; Alopaeus, Ville, Phase equilibria of binary systems of 3-methylthiophene with four different hydrocarbons, Fluid Phase Equilibria, 2010, 288, 1-2, 155-160, https://doi.org/10.1016/j.fluid.2009.11.004 . [all data]

Pokki, Uusi-Kyyny, et al., 2002
Pokki, Juha-Pekka; Uusi-Kyyny, Petri; Aittamaa, Juhani; Liukkonen, Simo, Vapor-Liquid Equilibrium for the 2-Methylpentane + 2-Methyl-2-propanol and + 2-Butanol Systems at 329 K, J. Chem. Eng. Data, 2002, 47, 2, 371-375, https://doi.org/10.1021/je0155296 . [all data]

Aucejo, Loras, et al., 1998
Aucejo, Antonio; Loras, Sonia; Muñoz, Rosa; Reich, Ricardo; Segura, Hugo, Isobaric Vapor-Liquid Equilibrium in the Systems 2-Methylpentane + Methyl 1,1-Dimethylethyl Ether, + Ethyl 1,1-Dimethylethyl Ether, and + Methyl 1,1-Dimethylpropyl Ether, J. Chem. Eng. Data, 1998, 43, 6, 973-977, https://doi.org/10.1021/je980090b . [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]

Waddington, Smith, et al., 1949
Waddington, G.; Smith, J.C.; Scott, D.W.; Huffman, H.M., Experimental vapor heat capacities and heats of vaporization of 2-methylpentane, 3-methylpentane and 2,3-dimethylbutane, J. Am. Chem. Soc., 1949, 71, 3902-3906. [all data]

Willingham, Taylor, et al., 1945
Willingham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D., Vapor pressures and boiling points of some paraffin, alkylcyclopentane, alkylcyclohexane, and alkylbenzene hydrocarbons, J. RES. NATL. BUR. STAN., 1945, 35, 3, 219-17, https://doi.org/10.6028/jres.035.009 . [all data]

Lemons and Felsing, 1943
Lemons, Joe Fred; Felsing, W.A., The Heats of Vaporization of Some Hexanes 1, J. Am. Chem. Soc., 1943, 65, 1, 46-48, https://doi.org/10.1021/ja01241a015 . [all data]

Williamham, Taylor, et al., 1945
Williamham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D., Vapor Pressures and Boiling Points of Some Paraffin, Alkylcyclopentane, Alkylcyclohexane, and Alkylbenzene Hydrocarbons, J. Res. Natl. Bur. Stand. (U.S.), 1945, 35, 3, 219-244, https://doi.org/10.6028/jres.035.009 . [all data]

Douslin and Huffman, 1946, 2
Douslin, D.R.; Huffman, H.M., Low-temperature thermal data on the five isometric hexanes, J. Am. Chem. Soc., 1946, 68, 1704-1708. [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]

Luo and Pacey, 1992
Luo, Y.-R.; Pacey, P.D., Effects of alkyl substitution on ionization energies of alkanes and haloalkanes and on heats of formation of their molecular cations. Part 2. Alkanes and chloro-, bromo- and iodoalkanes, Int. J. Mass Spectrom. Ion Processes, 1992, 112, 63. [all data]

Mautner(Meot-Ner), Sieck, et al., 1981
Mautner(Meot-Ner), M.; Sieck, L.W.; Ausloos, P., Ionization of normal alkanes: Enthalpy, entropy, structural, and isotope effects, J. Am. Chem. Soc., 1981, 103, 5342. [all data]

Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J., Ionization potentials of some molecules, J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]

Steiner, Giese, et al., 1961
Steiner, B.; Giese, C.F.; Inghram, M.G., Photoionization of alkanes. Dissociation of excited molecular ions, J. Chem. Phys., 1961, 34, 189. [all data]


Notes

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