Octane

• Formula: C₈H₁₈
• Molecular weight: 114.2285
• IUPAC Standard InChI: InChI=1S/C8H18/c1-3-5-7-8-6-4-2/h3-8H2,1-2H3 Copy

  
• IUPAC Standard InChIKey: TVMXDCGIABBOFY-UHFFFAOYSA-N Copy
• CAS Registry Number: 111-65-9
• 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:
  • Octane-d18-
  • Octane-1,2,3,4,5,6-d13
  • Octane-1,2,3,4-d9
  • Octane-1,2-d5
• Other names: n-Octane; n-C8H18; Oktan; Oktanen; Ottani; UN 1262
• 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
  • Henry's Law data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Reaction thermochemistry data
  • IR Spectrum
  • Fluid Properties
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • Reference simulation
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Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, Henry's Law 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:
DRB - Donald R. Burgess, Jr.
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

Constant pressure heat capacity of gas

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, Henry's Law 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Henry's Law 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(-αT_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

Henry's Law data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, 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 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)

Gas phase ion energetics data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law 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)

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

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law 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.

Good, 1972
Good, W.D., The enthalpies of combustion and formation of n-octane and 2,2,3,3-tetramethylbutane, J. Chem. Thermodyn., 1972, 4, 709-714. [all data]

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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]

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Prosen, E.J.; Rossini, F.D., Heats of combustion of eight normal paraffin hydrocarbons in the liquid state, J. Res. NBS, 1944, 33, 255-272. [all data]

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Scott D.W., Correlation of the chemical thermodynamic properties of alkane hydrocarbons, J. Chem. Phys., 1974, 60, 3144-3165. [all data]

Messerly J.F., 1967
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Hossenlopp I.A., 1981
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Barrow G.M., 1951
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Czarnota, 1993
Czarnota, I., Heat capacity of octane at high pressures, J. Chem. Thermodynam., 1993, 25, 355-359. [all data]

Banipal, Garg, et al., 1991
Banipal, T.S.; Garg, S.K.; Ahluwalia, J.C., Heat capacities and densities of liquid n-octane, n-nonane, n-decane, and n-hexadecane at temperatures from 318.15 to 373.15 K and at pressures up to 10 MPa, J. Chem. Thermodynam., 1991, 23, 923-931. [all data]

Trejo, Costas, et al., 1991
Trejo, L.M.; Costas, M.; Patterson, D., Excess heat capacity of organic mixtures, Internat. DATA Series, Selected Data Mixt., 1991, Ser. [all data]

Andreoli-Ball, Patterson, et al., 1988
Andreoli-Ball, L.; Patterson, D.; Costas, M.; Caceres-Alonso, M., Heat capacity and corresponding states in alkan-1-ol-n-alkane systems, J. Chem. Soc., Faraday Trans. 1, 1988, 84(11), 3991-4012. [all data]

Perez-Casas, Aicart, et al., 1988
Perez-Casas, S.; Aicart, E.; Trojo, L.M.; Costas, M., Excess heat capacity. Chlorobenzene-2,2,4,4,6,8,8-heptamethylnonane, Int. Data Ser., Sel. Data Mixtures, 1988, (2)A, 123. [all data]

Benson and D'Arcy, 1986
Benson, G.C.; D'Arcy, P.J., Heat capacities of binary mixtures of n-octane with each of the hexane isomers at 298.15 K, Can. J. Chem., 1986, 64, 2139-2141. [all data]

Tardajos, Aicart, et al., 1986
Tardajos, G.; Aicart, E.; Costas, M.; Patterson, D., Liquid structure and second-order mixing functions for benzene, toluene, and p-xylene with n-alkanes, J. Chem. Soc., Faraday Trans., 1986, 1 82, 2977-2987. [all data]

Lainez, Grolier, et al., 1985
Lainez, A.; Grolier, J.-P.E.; Wilhelm, E., Excess molar heat capacity and excess molar volume of 1,6-dichlorohexane + n-octane, Thermochim. Acta, 1985, 91, 243-248. [all data]

Lainez, Rodrigo, et al., 1985
Lainez, A.; Rodrigo, M.; Roux, A.H.; Grolier, J.-P.E.; Wilhelm, E., Relations between structure and thermodynamic properties. Heat capacities of polar substances (nitrobenzene and benzonitrile) in alkane solutions, Calorim. Anal. Therm., 1985, 16, 153-158. [all data]

Grigor'ev and Andolenko, 1984
Grigor'ev, B.A.; Andolenko, R.A., Investigation of the isobaric heat capacity of n-paraffinic hydrocarbons at atmospheric pressure, Izv. Vyssh. Ucheb. Zaved., Neft i Gaz, 1984, (2), 60-62. [all data]

Roux, Grolier, et al., 1984
Roux, A.H.; Grolier, J.-P.E.; Inglese, A.; Wilhelm, E., Excess molar enthalpies, excess molar heat capacities and excess molar volumes of (fluorobenzene + an n-alkane), Ber. Bunsenges. Phys. Chem., 1984, 88, 986-992. [all data]

Zaripov, 1982
Zaripov, Z.I., Experimental study of the isobaric heat capacity of liquid organic compounds with molecular weights of up to 4000 a.e.m., 1982, Teplomassoobmen Teplofiz. [all data]

Grolier, Inglese, et al., 1981
Grolier, J.P.E.; Inglese, A.; Roux, A.H.; Wilhelm, E., Thermodynamics of (1-chloronaphthalene + n-alkane): excess enthalpies, excess volumes and excess heat capacities, Ber. Bunsenges. Phys. Chem., 1981, 85, 768-772. [all data]

Shakirov and Lyubarskii, 1980
Shakirov, R.F.; Lyubarskii, M.V., Low-temperature heat capacity and thermodynamic functions of methyl trichlorothioacrylate, SPSTL Deposited Publication 3 KhP-D80, 1980, 19p. [all data]

Grigor'ev, Rastorguev, et al., 1975
Grigor'ev, B.A.; Rastorguev, Yu.L.; Yanin, G.S., Experimental determination of the isobaric specific heat of n-alkanes, Iz. Vyssh. Uchebn. Zaved. Neft Gaz 18, 1975, No.10, 63-66. [all data]

Connolly, Sage, et al., 1951
Connolly, T.J.; Sage, B.H.; Lacey, W.N., Isobaric heat capacities at bubble point. n-Hexane, methylcyclopentane, and n-octane, Ind. Eng. Chem., 1951, 43, 946-950. [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]

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]

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]

Ewing and Ochoa, 2003
Ewing, M.B.; Ochoa, J.C. Sanchez, The vapour pressures of n-octane determined using comparative ebulliometry, Fluid Phase Equilibria, 2003, 210, 2, 277-285, https://doi.org/10.1016/S0378-3812(03)00174-2 . [all data]

Stephenson and Malanowski, 1987
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Paul, Krug, et al., 1986
Paul, Hanns-Ingolf; Krug, Joseph; Knapp, Helmut, Measurements of VLE, hE and vE for binary mixtures of n-alkanes with n-alkylbenzenes, Thermochimica Acta, 1986, 108, 9-27, https://doi.org/10.1016/0040-6031(86)85073-0 . [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]

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McKay, R.A.; Sage, B.H., Latent Heat of Vaporization for n-Octane., J. Chem. Eng. Data, 1960, 5, 1, 21-24, https://doi.org/10.1021/je60005a005 . [all data]

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Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Henry's Law 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
  Cp,liquid	Constant pressure heat capacity of liquid
  IE (evaluated)	Recommended ionization energy
  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
  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
  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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