Heptane, 3-methyl-

• Formula: C₈H₁₈
• Molecular weight: 114.2285
• IUPAC Standard InChI: InChI=1S/C8H18/c1-4-6-7-8(3)5-2/h8H,4-7H2,1-3H3 Copy

  
• IUPAC Standard InChIKey: LAIUFBWHERIJIH-UHFFFAOYSA-N Copy
• CAS Registry Number: 589-81-1
• 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.
• Isotopologues:
  • 2-C2D5-Hexane
  • 2-C2H5-Hexane-d13
• Stereoisomers:
  • (S)-3-methylheptane
• Other names: 3-Methylheptane; 2-Ethylhexane
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • 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
• Other data available:
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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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

Constant pressure heat capacity of gas

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

Constant pressure heat capacity of liquid

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
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

Enthalpy of vaporization

Antoine Equation Parameters

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

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Enthalpy of fusion

Enthalpy of phase transition

Entropy of phase transition

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

=

By formula: C₈H₁₈ = C₈H₁₈

 +  =

By formula: C₈H₁₆ + H₂ = C₈H₁₈

=

By formula: C₈H₁₈ = C₈H₁₈

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)

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

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• GAS (13 mmHg, N2 ADDED, TOTAL PRESSURE 600 mmHg); BECKMAN IR-9 (GRATING); DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 2 cm^-1 resolution

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

• gas; HP-GC/MS/IRD

Mass spectrum (electron ionization)

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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

Spectrum

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Additional Data

References

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), 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]

Finke H.L., 1973
Finke H.L., 3-Methylpentane and 3-methylheptane: low-temperature thermodynamic properties, J. Chem. Thermodyn., 1973, 5, 247-257. [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]

Finke and Messerly, 1973
Finke, H.L.; Messerly, J.F., 3-Methylpentane and 3-methylheptane: low-temperature thermodynamic properties, J. Chem. Thermodynam., 1973, 5, 247-257. [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]

Finke and Messerly, 1973, 2
Finke, H.L.; Messerly, J.F., 3-Methylpentane and 3-Methylheptane: Low-temperature Thermo. Properties properties, J. Chem. Thermodyn., 1973, 5, 247. [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]

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]

An, Hu, et al., 1987
An, Xuwu; Hu, Riheng; Wang, Hu; Wu, Mali; Zou, Yongkuang, Enthalpies of Vaporization of α- and β-Pinene, Acta Phys. Chim. Sin., 1987, 3, 6, 668-671, https://doi.org/10.3866/PKU.WHXB19870621 . [all data]

Reid, 1972
Reid, Robert C., Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00, AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637 . [all data]

Osborne and Ginnings, 1947, 2
Osborne, Nathan S.; Ginnings, Defoe C., Measurements of heat of vaporization and heat capacity of a number of hydrocarbons, J. RES. NATL. BUR. STAN., 1947, 39, 5, 453-17, https://doi.org/10.6028/jres.039.031 . [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]

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]

Notes

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

• Symbols used in this document:
  

  Cp,gas	Constant pressure heat capacity of gas
  Cp,liquid	Constant pressure heat capacity of liquid
  Pc	Critical pressure
  S°gas	Entropy of gas at standard conditions
  S°liquid	Entropy of liquid at standard conditions
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Vc	Critical volume
  d(ln(kH))/d(1/T)	Temperature dependence parameter for Henry's Law constant
  k°H	Henry's Law constant at 298.15K
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔvapH	Enthalpy of vaporization
  ΔvapH°	Enthalpy of vaporization at standard conditions
  ρc	Critical density

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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