Octadecanoic acid

• Formula: C₁₈H₃₆O₂
• Molecular weight: 284.4772
• IUPAC Standard InChI: InChI=1S/C18H36O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h2-17H2,1H3,(H,19,20) Copy

  
• IUPAC Standard InChIKey: QIQXTHQIDYTFRH-UHFFFAOYSA-N Copy
• CAS Registry Number: 57-11-4
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Stearic acid; n-Octadecanoic acid; Humko Industrene R; Hydrofol Acid 150; Hystrene S-97; Hystrene T-70; Hystrene 80; Industrene R; Kam 1000; Kam 2000; Kam 3000; Neo-Fat 18; Neo-Fat 18-53; Neo-Fat 18-54; Neo-Fat 18-55; Neo-Fat 18-59; NAA 173; PD 185; Stearex Beads; Stearophanic acid; Steric acid; Vanicol; 1-Heptadecanecarboxylic acid; Heptadecanecarboxylic acid; Neo-fat 18-61; Pearl stearic; Century 1240; Dar-chem 14; Emersol 120; Emersol 132; Emersol 150; Formula 300; Glycon DP; Glycon TP; Glycon S-70; Glycon S-80; Glycon S-90; Groco 54; Groco 55; Groco 55L; Groco 58; Groco 59; Hy-phi 1199; Hy-phi 1205; Hy-phi 1303; Hy-phi 1401; Hydrofol acid 1655; Hydrofol acid 1855; Hydrofol 1895; Hystrene 4516; Hystrene 5016; Hystrene 7018; Hystrene 9718; Industrene 5016; Neo-Fat 18-S; Tegostearic 254; Tegostearic 255; Tegostearic 272; Cetylacetic acid; Industrene 8718; Industrene 9018; Barolub FTA; Loxiol G 20; Lunac S 20; Emersol 153; Century 1210; Century 1220; Century 1230; Emersol 6349; Hystrene 7018 FG; Hystrene 9718 NF FG; Industrene 4518; Industrene 7018 FG; n-Octadecylic acid; Pristerene 4904; Promulsin; Proviscol wax; Stearex; Tsubaki; Vis-Plus; Prifac 2918; Adeka Fatty Acid SA 910; Century 1224; Edenor C18; Hydrofol Acid 1895; Kiri stearic acid; Lunac S 40; SA 400 (fatty acid); WO 2 (fatty acid); Octadecanoic acid (stearic acid); Emersol 110 (Salt/Mix); Emery 400 (Salt/Mix)
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• Information on this page:
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • References
  • Notes
• Other data available:
  • Gas Chromatography
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Condensed phase thermochemistry data

Go To: Top, Phase change data, Reaction thermochemistry 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 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 solid

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

Enthalpy of vaporization

Antoine Equation Parameters

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

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Enthalpy of sublimation

Enthalpy of fusion

Entropy 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: C₁₈H₃₄O₂ + H₂ = C₁₈H₃₆O₂

2 +  =

By formula: 2H₂ + C₁₈H₃₂O₂ = C₁₈H₃₆O₂

3 +  =

By formula: 3H₂ + C₁₈H₃₀O₂ = C₁₈H₃₆O₂

 +  =

By formula: C₁₈H₃₄O₂ + H₂ = C₁₈H₃₆O₂

2 +  =

By formula: 2H₂ + C₁₈H₃₂O₂ = C₁₈H₃₆O₂

IR Spectrum

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

Data compiled by: Coblentz Society, Inc.

• SOLID; PERKIN-ELMER; DIGITIZED BY NIST FROM HARD COPY; 4 cm^-1 resolution
• SOLID (SPLIT MULL) $$ SEE SPECTRUM NO. 6411 "SOLUTION" SPECTRUM, AND 2010 "SOLID FILM" SPECTRUM; DOW KBr FOREPRISM-GRATING; DIGITIZED BY COBLENTZ SOCIETY (BATCH I) FROM HARD COPY; 2 cm^-1 resolution
• SOLUTION (10% CCl4 FOR 3800-1330, 10% CS2 FOR 1330-450 CM^-1); DOW KBr FOREPRISM-GRATING; DIGITIZED BY COBLENTZ SOCIETY (BATCH I) FROM HARD COPY; 2 cm^-1 resolution
• SOLUTION (2% CCl4 FOR 3800-1330, 2% CS2 FOR 1330-450 CM^-1); DOW KBr FOREPRISM-GRATING; DIGITIZED BY COBLENTZ SOCIETY (BATCH I) FROM HARD COPY; 2 cm^-1 resolution

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

• gas

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, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry 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.

Lebedeva, 1964
Lebedeva, N.D., Heats of combustion of monocarboxylic acids, Russ. J. Phys. Chem. (Engl. Transl.), 1964, 38, 1435-1437. [all data]

Adriaanse, Dekker, et al., 1965
Adriaanse, N.; Dekker, H.; Coops, J., Heats of combustion of normal saturated fatty acids and their methyl esters, Rec. Trav. Chim. Pays/Bas, 1965, 84, 393-407. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Medard and Thomas, 1952
Medard, L.; Thomas, M., Determination des chaleurs de combustion de douze composes organiques utilises dans les poudres et enplosies, Mem. Poudres, 1952, 34, 421-442. [all data]

Shkaraputa, Danilenko, et al., 1984
Shkaraputa, L.N.; Danilenko, V.V.; Sklyar, V.T.; Kendis, M.Sh.; Ratushnaya, V.I., Changes in enthalpy in the reaction of stearic acid with dextramine, Neftepererab. Neftekhim. (Moscow), 1984, 27, 31-32. [all data]

Swain, Silbert, et al., 1964
Swain, H.A., Jr.; Silbert, L.S.; Miller, J.G., The heats of combustion of aliphatic long chain peroxyacids, t-butyl peroxyesters, and related acids and esters, J. Am. Chem. Soc., 1964, 86, 2562-2566. [all data]

Emery and Benedict, 1911
Emery, A.G.; Benedict, F.G., The heat of combustion of compounds of physiological importance, Am. J. Physiol., 1911, 28, 301-307. [all data]

Singleton, Ward, et al., 1950
Singleton, W.S.; Ward, T.L.; Dollear, F.G., Physical properties of fatty acids. I. Some dilatometric and thermal properties of stearic acid in two polymorphic forms, J. Am. Oil Chem. Soc., 1950, 27, 143-146. [all data]

Schaake, van Miltenburg, et al., 1982
Schaake, R.C.F.; van Miltenburg, J.C.; De Kruif, C.G., Thermodynamic properties of the normal alkanoic acids. II. Molar heat capacities of seven even-numbered normal alkanoic acids, J. Chem. Thermodynam., 1982, 14, 771-778. [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]

Krafft, 1880
Krafft, F., The production of laurinaldehyde c(12)h(24)o, myristinaldehyde c(14)h(28)o, palmitinaldehyde c(16)h(32)o, stearinaldehyde c(18)h(36)o: I investigation of aldehydes, Ber. Dtsch. Chem. Ges., 1880, 13, 1413-8. [all data]

Schaake, van Miltenburg, et al., 1982, 2
Schaake, R.C.F.; van Miltenburg, J.C.; De Kruif, C.G., Thermodynamic properties of the normal alkanoic acids. II. Molar heat capacities of seven even-numbered normal alkanoic acids., J. Chem. Thermodyn., 1982, 14, 771-8. [all data]

Spizzichino, 1956
Spizzichino, C., Contribution a l'etude des tensions de vapeur et des chaleurs de vaporisation des acides gras, esters methyliques et alcools gras a des pressions inferieures a 1 mm de mercure, J. des Recherches du C.N.R.S., 1956, 34, 1-24. [all data]

Singleton, Ward, et al., 1950, 2
Singleton, W.S.; Ward, T.L.; Dollear, F.G., Physical Properties of Fatty Acids I. Some Dilatometric and Thermal Properties of Stearic Acid in Two Polymorphic Forms, J. Am. Oil Chem. Soc., 1950, 27, 143. [all data]

D'Souza and Teja, 1987
D'Souza, R.; Teja, A.S., The prediction of the vapor pressures of carboxylic acids, Chem. Eng. Commun., 1987, 61, 13. [all data]

Cappa, Lovejoy, et al., 2008
Cappa, Christopher D.; Lovejoy, Edward R.; Ravishankara, A.R., Evaporation Rates and Vapor Pressures of the Even-Numbered C ₈ -C ₁₈ Monocarboxylic Acids, J. Phys. Chem. A, 2008, 112, 17, 3959-3964, https://doi.org/10.1021/jp710586m . [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]

de Kruif, Schaake, et al., 1982
de Kruif, C.G.; Schaake, R.C.F.; van Miltenburg, J.C.; van der Klauw, K.; Blok, J.G., Thermodynamic properties of the normal alkanoic acids III. Enthalpies of vaporization and vapour pressures of 13 normal alkanoic acids, The Journal of Chemical Thermodynamics, 1982, 14, 8, 791-798, https://doi.org/10.1016/0021-9614(82)90176-8 . [all data]

Cramer, 1943
Cramer, K.S.N., Chem. Zentr. II, 1943, 2234. [all data]

Stull, 1947
Stull, Daniel R., Vapor Pressure of Pure Substances. Organic and Inorganic Compounds, Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022 . [all data]

Chattopadhyay and Ziemann, 2005
Chattopadhyay, Sulekha; Ziemann, Paul J., Vapor Pressures of Substituted and Unsubstituted Monocarboxylic and Dicarboxylic Acids Measured Using an Improved Thermal Desorption Particle Beam Mass Spectrometry Method, Aerosol Science and Technology, 2005, 39, 11, 1085-1100, https://doi.org/10.1080/02786820500421547 . [all data]

Chattopadhyay, Tobias, et al., 2001
Chattopadhyay, Sulekha; Tobias, Herbert J.; Ziemann, Paul J., A Method for Measuring Vapor Pressures of Low-Volatility Organic Aerosol Compounds Using a Thermal Desorption Particle Beam Mass Spectrometer, Anal. Chem., 2001, 73, 16, 3797-3803, https://doi.org/10.1021/ac010304j . [all data]

Davies and Malpass, 1961
Davies, Mansel; Malpass, V.E., 212. Heats of sublimation of straight-chain monocarboxylic acids, J. Chem. Soc., 1961, 1048, https://doi.org/10.1039/jr9610001048 . [all data]

Cox and Pilcher, 1970, 2
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press Inc., London, 1970, 643. [all data]

Davies and Malpass, 1961, 2
Davies, M.; Malpass, V.E., Heats of sublimation of straight-chain monocarboxylic acids, J. Chem. Soc., 1961, 1048-10. [all data]

Sato, Yoshimoto, et al., 1990
Sato, K.; Yoshimoto, N.; Suzuki, M.; Kobayashi, M.; Kaneko, F., Structure and transformation in polymorphism of petroselinic acid (cis-w-12-octadecenoic acid), J. Phys. Chem., 1990, 94, 3180-3185. [all data]

Moore, Koelmel, et al., 2007
Moore, David J.; Koelmel, Donald; Laura, Donna; Bedford, Eilidh, Infrared spectroscopy and differential scanning calorimetry studies of binary combinations of cis-6-octadecenoic acid and octadecanoic acid, Chemistry and Physics of Lipids, 2007, 150, 1, 109-115, https://doi.org/10.1016/j.chemphyslip.2007.06.217 . [all data]

Moreno, Cordobilla, et al., 2007
Moreno, Evelyn; Cordobilla, Raquel; Calvet, Teresa; Cuevas-Diarte, M.A.; Gbabode, Gabin; Negrier, Philippe; Mondieig, Denise; Oonk, Harry A.J., Polymorphism of even saturated carboxylic acids from n-decanoic to n-eicosanoic acid, New J. Chem., 2007, 31, 6, 947, https://doi.org/10.1039/b700551b . [all data]

Teixeira, Gonçalves da Silva, et al., 2006
Teixeira, A.C.T.; Gonçalves da Silva, A.M.P.S.; Fernandes, A.C., Phase behaviour of stearic acid--stearonitrile mixtures, Chemistry and Physics of Lipids, 2006, 144, 2, 160-171, https://doi.org/10.1016/j.chemphyslip.2006.09.001 . [all data]

Yu, Meng, et al., 2000
Yu, S.; Meng, S.; Tan, Z.; Li, L.; Zhang, J., Taiyangneng Xuebao, 2000, 21, 2, 171. [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]

Eykman, 1889
Eykman, J.F., Zur kryoskopischen Molekulargewichtsbestimmung, Z. Physik. Chem., 1889, 4, 497-519. [all data]

Rogers, Hoyte, et al., 1978
Rogers, D.W.; Hoyte, O.P.A.; Ho, R.K.C., Heats of hydrogenation of large molecules. Part 2. Six unsaturated and polyunsaturated fatty acids, J. Chem. Soc. Faraday Trans. 1, 1978, 74, 46-52. [all data]

Notes

Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  Pc	Critical pressure
  Ptriple	Triple point pressure
  S°solid,1 bar	Entropy of solid at standard conditions (1 bar)
  Tboil	Boiling point
  Tc	Critical temperature
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  ΔHtrs	Enthalpy of phase transition
  ΔStrs	Entropy of phase transition
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions
  ΔvapH	Enthalpy of vaporization

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