Heptane, 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-215.5 ± 1.3kJ/molCcbProsen and Rossini, 1945ALS
Quantity Value Units Method Reference Comment
gas459.49 ± 0.88J/mol*KN/AMesserly J.F., 1971GT

Constant pressure heat capacity of gas

Cp,gas (J/mol*K) Temperature (K) Reference Comment
186.13298.15Colgate S.O., 1990GT
202.07323.15
230.06373.15
248.37408.15
265.52448.15

Constant pressure heat capacity of gas

Cp,gas (J/mol*K) Temperature (K) Reference Comment
135.65200.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 good agreement with experimental data available for alkanes. However, large uncertainties could be expected at high temperatures.; GT
173.89273.15
187.2 ± 0.2298.15
188.20300.
241.25400.
288.78500.
329.28600.
363.17700.
391.62800.
416.31900.
436.811000.
454.801100.
470.701200.
485.341300.
497.901400.
510.451500.

Condensed 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Δfliquid-255.2 ± 1.3kJ/molCcbProsen and Rossini, 1945ALS
Quantity Value Units Method Reference Comment
Δcliquid-5465.5 ± 1.2kJ/molCcbProsen and Rossini, 1945Corresponding Δfliquid = -255.1 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δcliquid-5447.1kJ/molCcbFajans, 1920Corresponding Δfliquid = -273. kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Δcliquid-5274.6kJ/molCcbRichards and Jesse, 1910At 293 K; Corresponding Δfliquid = -446.0 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity Value Units Method Reference Comment
liquid356.39J/mol*KN/AMesserly and Finke, 1971DH

Constant pressure heat capacity of liquid

Cp,liquid (J/mol*K) Temperature (K) Reference Comment
252.00298.15Messerly and Finke, 1971T = 11 to 370 K.; DH
251.58298.15Osborne and Ginnings, 1947T = 283 to 318 K.; DH

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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
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
Tboil390.7 ± 0.8KAVGN/AAverage of 37 out of 38 values; Individual data points
Quantity Value Units Method Reference Comment
Tfus163. ± 2.KAVGN/AAverage of 14 values; Individual data points
Quantity Value Units Method Reference Comment
Ttriple160. ± 9.KAVGN/AAverage of 10 values; Individual data points
Quantity Value Units Method Reference Comment
Tc559.7 ± 0.1KN/ADaubert, 1996 
Tc559.7KN/AAbara, Jennings, et al., 1988Uncertainty assigned by TRC = 0.2 K; TRC
Tc559.6KN/AMajer and Svoboda, 1985 
Tc559.56KN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.4 K; TRC
Tc559.57KN/AAmbrose, Cox, et al., 1960Uncertainty assigned by TRC = 0.2 K; Visual, PRT, IPTS-48; TRC
Quantity Value Units Method Reference Comment
Pc25.0 ± 0.2barN/ADaubert, 1996 
Pc25.00barN/AAbara, Jennings, et al., 1988Uncertainty assigned by TRC = 0.40 bar; TRC
Pc24.842barN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.4053 bar; TRC
Quantity Value Units Method Reference Comment
Vc0.488l/molN/ADaubert, 1996 
Quantity Value Units Method Reference Comment
ρc2.05 ± 0.02mol/lN/ADaubert, 1996 
ρc2.05mol/lN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.04 mol/l; TRC
Quantity Value Units Method Reference Comment
Δvap39. ± 5.kJ/molAVGN/AAverage of 6 values; Individual data points

Reduced pressure boiling point

Tboil (K) Pressure (bar) Reference Comment
389.21.01Aldrich Chemical Company Inc., 1990BS

Enthalpy of vaporization

ΔvapH (kJ/mol) Temperature (K) Method Reference Comment
33.26390.8N/AMajer and Svoboda, 1985 
39.8300.AStephenson and Malanowski, 1987Based on data from 285. to 392. K.; AC
41.6268.IPStephenson and Malanowski, 1987Based on data from 233. to 283. K. See also Osborn and Douslin, 1974.; AC
38.7 ± 0.1313.CMajer, Svoboda, et al., 1979AC
37.3 ± 0.1333.CMajer, Svoboda, et al., 1979AC
36.0 ± 0.1353.CMajer, Svoboda, et al., 1979AC
38.1330.MMWillingham, Taylor, et al., 1945Based on data from 315. to 391. K.; AC

Enthalpy of vaporization

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

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Temperature (K) A (kJ/mol) β Tc (K) Reference Comment
298. to 353.57.870.2919559.6Majer and Svoboda, 1985 

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
233. to 283.4.845621718.531-29.682Osborn and Douslin, 1974Coefficents calculated by NIST from author's data.
314.86 to 391.694.042271337.468-59.457Williamham, Taylor, et al., 1945 

Enthalpy of fusion

ΔfusH (kJ/mol) Temperature (K) Reference Comment
11.92064.19Messerly and Finke, 1971DH
11.92164.2Domalski and Hearing, 1996AC

Entropy of fusion

ΔfusS (J/mol*K) Temperature (K) Reference Comment
72.6064.19Messerly and Finke, 1971DH

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:


Reaction 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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

Octane = Heptane, 2-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
Δr-5.23 ± 0.92kJ/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Hydrogen + 1-Heptene, 2-methyl- = Heptane, 2-methyl-

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
Δr-115.1 ± 0.7kJ/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane

Hydrogen + 1-Heptene, 6-methyl- = Heptane, 2-methyl-

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
Δr-126.4 ± 2.0kJ/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane

Heptane, 2-methyl- = Heptane, 3-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
Δr1.86 ± 0.42kJ/molEqkRoganov, Kabo, et al., 1972gas phase; At 1368 K

Heptane, 2-methyl- = Heptane, 4-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
Δr1.3 ± 0.4kJ/molEqkRoganov, Kabo, et al., 1972gas phase; At 368 K

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
0.00027 QN/ASeveral references are given in the list of Henry's law constants but not assigned to specific species.
0.00027 QN/A missing citation give several references for the Henry's law constants but don't assign them to specific species.

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Henry's Law data, IR Spectrum, Mass spectrum (electron ionization), References, Notes

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

Data evaluated as indicated in comments:
L - Sharon G. Lias

Data compiled as indicated in comments:
LL - Sharon G. Lias and Joel F. Liebman
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

Quantity Value Units Method Reference Comment
IE (evaluated)9.84 ± 0.10eVN/AN/AL

Ionization energy determinations

IE (eV) Method Reference Comment
9.76ESTLuo and Pacey, 1992LL
9.84 ± 0.10EVALLias, 1982LBLHLM
9.74 ± 0.15EQMautner(Meot-Ner), Sieck, et al., 1981LLK

IR Spectrum

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

Gas Phase Spectrum

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IR spectrum
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Additional Data

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Owner NIST Standard Reference Data Program
Collection (C) 2018 copyright by the U.S. Secretary of Commerce
on behalf of the United States of America. All rights reserved.
Origin NIST Mass Spectrometry Data Center
State gas
Instrument HP-GC/MS/IRD

This IR spectrum is from the NIST/EPA Gas-Phase Infrared Database .


Mass spectrum (electron ionization)

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, IR Spectrum, References, Notes

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

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

Spectrum

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Mass spectrum
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Additional Data

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Due to licensing restrictions, this spectrum cannot be downloaded.

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 Japan AIST/NIMC Database- Spectrum MS-NW-4071
NIST MS number 230535

All mass spectra in this site (plus many more) are available from the NIST/EPA/NIH Mass Spectral Library. Please see the following for information about the library and its accompanying search program.


References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), 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]

Messerly J.F., 1971
Messerly J.F., Low-temperature thermal properties of 2-methylheptane and 2-methyldecane: the thermodynamic properties of 2-methylalkanes, J. Chem. Thermodyn., 1971, 3, 675-687. [all data]

Colgate S.O., 1990
Colgate S.O., Acoustical determination of ideal gas heat capacities of three C-8 compounds, Fluid Phase Equilib., 1990, 60, 191-203. [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]

Fajans, 1920
Fajans, K., Die Energie der Atombindungen im Diamanten und in aliphatischen Kohlenwasserstoffen, Ber., 1920, 53, 643-665. [all data]

Richards and Jesse, 1910
Richards, T.W.; Jesse, R.H., Jr., The heats of combustion of the octanes and xylenes, J. Am. Chem. Soc., 1910, 32, 268-298. [all data]

Messerly and Finke, 1971
Messerly, J.F.; Finke, H.L., Low-temperature thermal properties of 2-methylheptane and 2-methyldecane: the thermodynamic properties of the 2-methylalkanes, J. Chem. Thermodynam., 1971, 3, 675-687. [all data]

Osborne and Ginnings, 1947
Osborne, N.S.; Ginnings, D.C., Measurements of heat of vaporization and heat capacity of a number of hydrocarbons, J. Res. NBS, 1947, 39, 453-477. [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]

Abara, Jennings, et al., 1988
Abara, J.A.; Jennings, D.W.; Kay, W.B.; Teja, A.S., Phase Behavior in the Critical Region of Six Binary Mixtures of 2-Methylalkanes, J. Chem. Eng. Data, 1988, 33, 242. [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]

McMicking and Kay, 1965
McMicking, J.H.; Kay, W.B., Vapor Pressures and Saturated Liquid and Vapor Densities of The Isomeric Heptanes and Isomeric Octanes, Proc., Am. Pet. Inst., Sect. 3, 1965, 45, 75-90. [all data]

Ambrose, Cox, et al., 1960
Ambrose, D.; Cox, J.D.; Townsend, R., The critical temperatures of forty organic compounds, Trans. Faraday Soc., 1960, 56, 1452. [all data]

Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc., Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [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]

Osborn and Douslin, 1974
Osborn, Ann G.; Douslin, Donald R., Vapor-pressure relations for 15 hydrocarbons, J. Chem. Eng. Data, 1974, 19, 2, 114-117, https://doi.org/10.1021/je60061a022 . [all data]

Majer, Svoboda, et al., 1979
Majer, Vladimír; Svoboda, Václav; Hála, Slavoj; Pick, Jirí, Temperature dependence of heats of vaporization of saturated hydrocarbons C5-C8; Experimental data and an estimation method, Collect. Czech. Chem. Commun., 1979, 44, 3, 637-651, https://doi.org/10.1135/cccc19790637 . [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]

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]

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]

Prosen and Rossini, 1945, 2
Prosen, E.J.; Rossini, F.D., Heats of isomerization of the 18 octanes, J. Res. NBS, 1945, 34, 163-174. [all data]

Rogers, Dejroongruang, et al., 1992
Rogers, D.W.; Dejroongruang, K.; Samuel, S.D.; Fang, W.; Zhao, Y., Enthalpies of hydrogenation of the octenes and the methylheptenes, J. Chem. Thermodyn., 1992, 24, 561-565. [all data]

Roganov, Kabo, et al., 1972
Roganov, G.N.; Kabo, G.Ya.; Andreevskii, D.N., Thermodynamics of the isomerization of methylpentanes and methylheptanes, Neftekhimiya, 1972, 12, 495-500. [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]

Lias, 1982
Lias, S.G., Thermochemical information from ion-molecule rate constants, Ion Cyclotron Reson. Spectrom. 1982, 1982, 409. [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]


Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Henry's Law data, Gas phase ion energetics data, IR Spectrum, Mass spectrum (electron ionization), References