Octadecane

• Formula: C₁₈H₃₈
• Molecular weight: 254.4943
• IUPAC Standard InChI: InChI=1S/C18H38/c1-3-5-7-9-11-13-15-17-18-16-14-12-10-8-6-4-2/h3-18H2,1-2H3 Copy

  
• IUPAC Standard InChIKey: RZJRJXONCZWCBN-UHFFFAOYSA-N Copy
• CAS Registry Number: 593-45-3
• 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.
• Other names: n-Octadecane; Octadecan
• 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
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Henry's Law data
  • IR Spectrum
  • Gas Chromatography
• Options:
  • Switch to SI units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, 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 compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Phase change data

Go To: Top, Gas phase thermochemistry 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:
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

Enthalpy of vaporization

Antoine Equation Parameters

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

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Enthalpy of phase transition

Entropy of phase transition

Mass spectrum (electron ionization)

Go To: Top, Gas phase thermochemistry data, Phase change 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

Notice: This spectrum may be better viewed with a Javascript and HTML 5 enabled browser.

For Zoom

1.) Enter the desired X axis range (e.g., 100, 200)

2.) Check here for automatic Y scaling

3.) Press here to zoom

Additional Data

References

Go To: Top, Gas phase thermochemistry data, Phase change 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]

Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]

Matsui and Arakawa, 1932
Matsui, M.; Arakawa, S., Mem. Coll. Sci., Univ. Kyoto, Ser. A, 1932, 15, 189. [all data]

Von Braun and Sobecki, 1911
Von Braun, J.; Sobecki, W., Chem. Ber., 1911, 44, 1470. [all data]

Sorabji, 1885
Sorabji, K.B.B., J. Chem. Soc., 1885, 47, 37-41. [all data]

Messerly, Guthrie, et al., 1967
Messerly, J.F.; Guthrie, G.B.; Todd, S.S.; Finke, H.L., Low-Temperature Thermal Data for n-Pentane, n-Heptadecane and n-Octadecane. Revised Thermodynamic Functions for ther n-Alkanes, C5 - C18, J. Chem. Eng. Data, 1967, 12, 338-46. [all data]

Parks, Moore, et al., 1949
Parks, G.S.; Moore, G.E.; Renquist, M.L.; Naylor, B.F.; McClaine, L.A.; Fujii, P.S.; Hatton, J.A., Thermal Data on Organic Compounds. XXV. Some Heat Capacity, Entropy and Free Energy Data for Nine Hydrocarbons of High Molecular Weight, J. Am. Chem. Soc., 1949, 71, 10, 3386, https://doi.org/10.1021/ja01178a034 . [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]

Anselme, Gude, et al., 1990
Anselme, M.J.; Gude, M.; Teja, A.S., The Critical Temperatures and Densities of the n-Alkanes from Pentane to Octadecane, Fluid Phase Equilib., 1990, 57, 317-26. [all data]

Rosenthal and Teja, 1989
Rosenthal, D.J.; Teja, A.S., The Critical Properties of n-Alkanes Using a Low-Residence Time Flow Apparatus, AIChE J., 1989, 35, 1829. [all data]

Teja, Lee, et al., 1989
Teja, A.S.; Lee, R.J.; Rosenthal, D.J.; Anselme, M.J., Correlation of the Critical Properties of Alkanes and Alkanols in 5th IUPAC Conference on Alkanes and AlkanolsGradisca, 1989. [all data]

Ambrose, 1963
Ambrose, D., Critical Temperatures of Some Phenols and Other Organic Compounds, Trans. Faraday Soc., 1963, 59, 1988. [all data]

Morawetz, 1972
Morawetz, Ernst, Correlation of sublimation enthalpies at 298.15 K with molecular structure for planar aromatic hydrocarbons, The Journal of Chemical Thermodynamics, 1972, 4, 3, 461-467, https://doi.org/10.1016/0021-9614(72)90030-4 . [all data]

Morgan and Kobayashi, 1994
Morgan, David L.; Kobayashi, Riki, Direct vapor pressure measurements of ten n-alkanes m the 10-C28 range, Fluid Phase Equilibria, 1994, 97, 211-242, https://doi.org/10.1016/0378-3812(94)85017-8 . [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]

Macknick and Prausnitz, 1979
Macknick, A. Brian; Prausnitz, John M., Vapor pressures of high-molecular-weight hydrocarbons, J. Chem. Eng. Data, 1979, 24, 3, 175-178, https://doi.org/10.1021/je60082a012 . [all data]

Allemand, Jose, et al., 1986
Allemand, Nadine; Jose, Jacques; Merlin, J.C., Mesure des pressions de vapeur d'hydrocarbures C10 A C18n-alcanes etn-alkylbenzenes dans le domaine 3-1000 pascal, Thermochimica Acta, 1986, 105, 79-90, https://doi.org/10.1016/0040-6031(86)85225-X . [all data]

Nováková and Novák, 1977
Nováková, N.; Novák, J., Measurement of heats of vaporization by means of a gas chromatograph, Journal of Chromatography A, 1977, 135, 1, 13-24, https://doi.org/10.1016/S0021-9673(00)86297-4 . [all data]

Ubbelohde, 1938
Ubbelohde, A.R., Structure and thermodynamic properties of long-chain compounds, Trans. Faraday Soc., 1938, 34, 282, https://doi.org/10.1039/tf9383400282 . [all data]

Krafft, 1882
Krafft, F., Ueber neunzehn höhere Normalparaffine Cn H2n + 2 und ein einfaches Volumgesetz für den tropfbar flüssigen Zustand. I, Ber. Dtsch. Chem. Ges., 1882, 15, 2, 1687-1711, https://doi.org/10.1002/cber.18820150258 . [all data]

Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E., The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [all data]

Bradley and Shellard, 1949
Bradley, R.S.; Shellard, A.D., The rate of evaporation of droplets. III. Vapour pressures and rates of evaporation of straight-chain paraffin hydrocarbons, Proc. Roy. Soc. London A, 1949, 198, 239-251. [all data]

Jones, 1960
Jones, A.H., Sublimation Pressure Data for Organic Compounds., J. Chem. Eng. Data, 1960, 5, 2, 196-200, https://doi.org/10.1021/je60006a019 . [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press Inc., London, 1970, 643. [all data]

Barbillon, Schuffenecker, et al., 1991
Barbillon, P.; Schuffenecker, L.; Dellacherie, J.; Balesdent, D.; Dirande, M., Variation d'enthalpie subie de 260 K a 340 K par les n-paraffines, comprises entrel'octadecane et l'hexacosane, J. Chim. Phys. Phys.-Chim. Biol., 1991, 88, 91-113. [all data]

Kolesnikov and Syunyaev, 1985
Kolesnikov, S.I.; Syunyaev, Z.I., Phase transitions in the melting and crystallization of n-C₁₈H₃₈ and n-C₂₀H₄₂, Zhur. Prikl. Khim. (Leningrad), 1985, 58(10), 2267-2271. [all data]

Messerly, Guthrie, et al., 1967, 2
Messerly, J.F.; Guthrie, G.B.; Todd, S.S.; Finke, H.L., Low-temperature thermal data for n-pentane, n-heptadecane, and n-octadecane, J. Chem. Eng. Data, 1967, 12, 338-346. [all data]

Mondieig, Rajabalee, et al., 2004
Mondieig, D.; Rajabalee, F.; Metivaud, V.; Oonk, H.A.J.; Cuevas-Diarte, M.A., n -Alkane Binary Molecular Alloys, Chem. Mater., 2004, 16, 5, 786-798, https://doi.org/10.1021/cm031169p . [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]

Parks, Moore, et al., 1949, 2
Parks, G.S.; Moore, G.E.; Renquist, M.L.; Naylor, B.F.; McClaine, L.A.; Fujii, P.S.; Hatton, J.A., Thermal data on organic compounds. XXV. Some heat capacity, entropy and free energy data for nine hydrocarbons of high molecular weight, J. Am. Chem. Soc., 1949, 71, 3386-3389. [all data]

Claudy and Letoffe, 1991
Claudy, P.; Letoffe, J.M., Phase transitions in even n-alkanes CnH2n+2, n = 16-28. Characterization by differential calorimetric analysis and by thermooptical analysis. Effect of deuteration, Calorim. Anal. Therm., 1991, 22, 281-290. [all data]

Schaerer, Busso, et al., 1955
Schaerer, A.A.; Busso, C.J.; Smith, A.E.; Skinner, L.B., Properties of pure normal alkanes in the C₁₇ to C₃₆ range, J. Am. Chem. Soc., 1955, 77, 2017-2019. [all data]

Notes

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

• Symbols used in this document:
  

  Pc	Critical pressure
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  Vc	Critical volume
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation 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
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.