Heptane

• Formula: C₇H₁₆
• Molecular weight: 100.2019
• IUPAC Standard InChI: InChI=1S/C7H16/c1-3-5-7-6-4-2/h3-7H2,1-2H3 Copy

  
• IUPAC Standard InChIKey: IMNFDUFMRHMDMM-UHFFFAOYSA-N Copy
• CAS Registry Number: 142-82-5
• 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:
  • Heptane-1,2,3,4,5,6-d13
  • Heptane-1,2,3,4-d9
  • Heptane-1,2,3,-d7
  • Heptane-1-d3
  • Heptane-d16
• Other names: n-Heptane; Dipropylmethane; Heptyl hydride; Skellysolve C; n-C7H16; Eptani; Heptan; Heptanen; Gettysolve-C; NSC 62784
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Phase change data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Henry's Law data
  • IR Spectrum
  • Fluid Properties
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
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Gas phase thermochemistry data

Go To: Top, Phase change data, Gas phase ion energetics data, 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 compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow

Constant pressure heat capacity of gas

Constant pressure heat capacity of gas

Phase change data

Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, 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 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

Enthalpy of vaporization

Enthalpy of vaporization

Δ_vapH = A exp(-βT_r) (1 − T_r)^β
    Δ_vapH = Enthalpy of vaporization (at saturation pressure) (kJ/mol)
    T_r = reduced temperature (T / T_c)

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Antoine Equation Parameters

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

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Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Temperature of phase transition

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Phase change data, 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
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron

Ionization energy determinations

Appearance energy determinations

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, Phase change data, Gas phase ion energetics data, 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]

Davies and Gilbert, 1941
Davies, G.F.; Gilbert, E.C., Heats of combustion and formation of the nine isomeric heptanes in the liquid state, J. Am. Chem. Soc., 1941, 63, 2730-2732. [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]

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Pitzer K.S., Thermodynamics of gaseous paraffins. Specific heat and related properties, Ind. Eng. Chem., 1944, 36, 829-831. [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., 1947
Waddington G., An improved flow calorimeter. Experimental vapor heat capacities and heats of vaporization of n-heptane and 2,2,3-trimethylbutane, J. Am. Chem. Soc., 1947, 69, 22-30. [all data]

Ambrose and Tsonopoulos, 1995
Ambrose, D.; Tsonopoulos, C., Vapor-Liquid Critical Properties of Elements and Compounds. 2. Normal Alkenes, J. Chem. Eng. Data, 1995, 40, 531-546. [all data]

Zawisza and Vejrosta, 1982
Zawisza, A.; Vejrosta, J., High-pressure liquid-vapor equilibria, critical stat, and p(V, T, x) up to 573.15 K and 5.066 MPa for (heptane + propan-1-ol), J. Chem. Thermodyn., 1982, 14, 239-49. [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]

Segura, Wisniak, et al., 2002
Segura, Hugo; Wisniak, Jaime; Galindo, Graciela; Reich, Ricardo, Phase Equilibria in the Systems 1-Hexene + Heptane and 1-Hexene + Ethyl 1,1-Dimethylethyl Ether + Heptane at 94.00 kPa, Physics and Chemistry of Liquids, 2002, 40, 1, 67-81, https://doi.org/10.1080/00319100208086650 . [all data]

Ortega, González, et al., 2001
Ortega, Juan; González, Carmelo; Galván, Salvador, Vapor-Liquid Equilibria for Binary Systems Composed of a Propyl Ester (Ethanoate, Propanoate, Butanoate) + an n -Alkane (C ₇ , C ₉ ), J. Chem. Eng. Data, 2001, 46, 4, 904-912, https://doi.org/10.1021/je000358a . [all data]

Stephenson and Malanowski, 1987
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Forziati, Norris, et al., 1949
Forziati, Alphonse F.; Norris, William R.; Rossini, Frederick D., Vapor pressures and boiling points of sixty API-NBS hydrocarbons, J. RES. NATL. BUR. STAN., 1949, 43, 6, 555-17, https://doi.org/10.6028/jres.043.050 . [all data]

Michou-Saucet, Jose, et al., 1984
Michou-Saucet, Marie-Annie; Jose, Jacques; Michou-Saucet, Christian; Merlin, J.C., Pressions de vapeur et enthalpies libres d'exces de systemes binaires: Hexamethylphosphorotriamide (HMPT) + n-hexane; n-heptane; n-octane: A 298,15 K; 303,15 K; 313,15 K; 323,15 K; 333,15 K, Thermochimica Acta, 1984, 75, 1-2, 85-106, https://doi.org/10.1016/0040-6031(84)85009-1 . [all data]

Sipowska and Wieczorek, 1984
Sipowska, Jadwiga T.; Wieczorek, Stefan A., Vapour pressures and excess Gibbs free energies of (cyclohexanol + n-heptane) between 303.147 and 373.278 K, The Journal of Chemical Thermodynamics, 1984, 16, 7, 693-699, https://doi.org/10.1016/0021-9614(84)90051-X . [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]

Van Ness, Soczek, et al., 1967
Van Ness, Hendrick C.; Soczek, C.A.; Peloquin, G.L.; Machado, R.L., Thermodynamic excess properties of three alcohol-hydrocarbon systems, J. Chem. Eng. Data, 1967, 12, 2, 217-224, https://doi.org/10.1021/je60033a017 . [all data]

Waddington, Todd, et al., 1947
Waddington, Guy; Todd, Samuel S.; Huffman, Hugh M., An Improved Flow Calorimeter. Experimental Vapor Heat Capacities and Heats of Vaporization of n-Heptane and 2,2,3-Trimethylbutane ¹, J. Am. Chem. Soc., 1947, 69, 1, 22-30, https://doi.org/10.1021/ja01193a007 . [all data]

Thomson, 1946
Thomson, George Wm., The Antoine Equation for Vapor-pressure Data., Chem. Rev., 1946, 38, 1, 1-39, https://doi.org/10.1021/cr60119a001 . [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]

Pitzer K.S., 1940
Pitzer K.S., The thermodynamics of n-heptane and 2,2,4-trimethylpentane, including heat capacities, heats of fusion and vaporization and entropies, J. Am. Chem. Soc., 1940, 62, 1224-1227. [all data]

Smith, 1940
Smith, E.R., Boiling points of n-heptane and 2,2,4-trimethylpentane over the range 100- to 1,500-millimeter pressure, J. RES. NATL. BUR. STAN., 1940, 24, 3, 229-17, https://doi.org/10.6028/jres.024.010 . [all data]

Carruth and Kobayashi, 1973
Carruth, Grant F.; Kobayashi, Riki, Vapor pressure of normal paraffins ethane through n-decane from their triple points to about 10 mm mercury, J. Chem. Eng. Data, 1973, 18, 2, 115-126, https://doi.org/10.1021/je60057a009 . [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]

Bondi, 1963
Bondi, A., Heat of Siblimation of Molecular Crystals: A Catalog of Molecular Structure Increments., J. Chem. Eng. Data, 1963, 8, 3, 371-381, https://doi.org/10.1021/je60018a027 . [all data]

Van Miltenburg, Van den Berg, et al., 1987
Van Miltenburg, J.C.; Van den Berg, G.J.K.; Van Bommel, M.J., Construction of an adiabatic calorimeter. Measurements of the molar heat capacity of synthetic sapphire and of n-heptane, J. Chem. Thermodynam., 1987, 19, 1129-1137. [all data]

Schaake, Offringa, et al., 1979
Schaake, R.C.F.; Offringa, J.C.A.; van der Berg, G.J.K.; van Miltenburg, J.C., Phase transitions in solids, studied by adiabatic calorimetry. I. Design and test of an automatic adiabatic calorimeter, J. Royal Netherlands Chem. Soc., 1979, 98, 408-412. [all data]

Huffman, Gross, et al., 1961
Huffman, H.M.; Gross, M.E.; Scott, D.W.; McCullough, I.P., Low temperature thermodynamic properties of six isomeric heptanes, J. Phys. Chem., 1961, 65, 495-503. [all data]

McCullough and Messerly, 1961
McCullough, J.P.; Messerly, J.F., The chemical thermodynamic properties of hydrocarbons and related substances, Bureau of Mines Bulletin, 1961, 596, pp. [all data]

Douglas, Furukawa, et al., 1954
Douglas, T.B.; Furukawa, G.T.; McCoskey, R.E.; Ball, A.F., Calorimetric properties of normal heptane from 0 to 520 K, J. Res., 1954, NBS 53, 139-153. [all data]

Ginnings and Furukawa, 1953
Ginnings, D.C.; Furukawa, G.T., Heat capacity standards for the range 14 to 1200°K, J. Am. Chem. Soc., 1953, 75, 522-527. [all data]

Meijer, Blok, et al., 1977
Meijer, E.L.; Blok, J.G.; Kroon, J.; Oonk, H.A.J., The carvoxime system. IV. Heat capacities and enthalpies of melting of DL-carvoxime, L-carvoxime and standard n-heptane, Thermochim. Acta, 1977, 20, 325-334. [all data]

Van Miltenburg, 1972
Van Miltenburg, J.C., Construction of an adiabatic calorimeter. Thermodynamic properties of standard n-heptane from 155 to 270K and of 2,2-dichloropropane from 135 to 270K, J. Chem. Thermodynam., 1972, 4, 773-782. [all data]

Oetting F.L., 1963
Oetting F.L., The heat capacity and entropy of 2-methyl-2-propanol from 15 to 330 K, J. Phys. Chem., 1963, 67, 2757-2761. [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]

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Huffman, H.M.; Parks, G.S.; Thomas, S.B., Thermal data on organic compounds. VIII. The heat capacities, entropies and free energies of the isomeric heptanes, J. Am. Chem. Soc., 1930, 52, 3241-3251. [all data]

Parks, Huffman, et al., 1930
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Holzhauer and Ziegler, 1975
Holzhauer, J.K.; Ziegler, W.T., Temperature dependence of excess thermodynamic properties of n-heptane-toluene, methylcyclohexane-toluene, and n-heptane-methylcyclohexane systems, J. Phys. Chem., 1975, 79(6), 590-604. [all data]

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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]

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Lias, Ausloos, et al., 1976
Lias, S.G.; Ausloos, P.; Horvath, Z., Charge transfer reactions in alkane and cycloalkane systems. Estimated ionization potentials, Int. J. Chem. Kinet., 1976, 8, 725. [all data]

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Brehm, B., Massenspektrometrische Untersuchung der Photoionisation von Molekulen, Z. Naturforsch., 1966, 21a, 196. [all data]

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

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

Lewis and Hamill, 1970
Lewis, D.; Hamill, W.H., Excited states of neutral molecular fragments from appearance potentials by electron impact in a mass spectrometer, J. Chem. Phys., 1970, 52, 6348. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,gas	Constant pressure heat capacity of gas
  IE (evaluated)	Recommended ionization energy
  Pc	Critical pressure
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Ttrs	Temperature of phase transition
  Vc	Critical volume
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔsubH	Enthalpy of sublimation
  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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