Octanoic acid
- Formula: C8H16O2
- Molecular weight: 144.2114
- IUPAC Standard InChIKey: WWZKQHOCKIZLMA-UHFFFAOYSA-N
- CAS Registry Number: 124-07-2
- 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-Caprylic acid; n-Octanoic acid; n-Octoic acid; n-Octylic acid; Neo-Fat 8; Caprylic acid; Enantic acid; Octylic acid; 1-Heptanecarboxylic acid; Heptane-1-carboxylic acid; Octic acid; Hexacid 898; C-8 Acid; Kyselina kaprylova; Lunac 8-95; Emery 657; Octoic acid; Prifac 2901; 1-Octanoic acid; NSC 5024; Prifrac 2901
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Gas phase thermochemistry data
Go To: Top, 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: Donald R. Burgess, Jr.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -132.5 ± 0.31 | kcal/mol | Ccb | Adriaanse, Dekker, et al., 1965 | Value computed using ΔfHliquid° from Adriaanse, Dekker, et al., 1965 and ΔvapH° value of 19.2 kcal/mol from Baccanari, Novinski, et al., 1968. estimated uncertainty |
ΔfH°gas | -133.0 | kcal/mol | N/A | Lebedeva, 1964 | Value computed using ΔfHliquid° value of -636.89±0.54 kj/mol from Lebedeva, 1964 and ΔvapH° value of 80.3 kj/mol from missing citation. |
ΔfH°gas | -132.4 ± 0.26 | kcal/mol | N/A | Lebedeva, 1964 | Value computed using ΔfHliquid° value of -636.89±0.54 kj/mol from Lebedeva, 1964 and ΔvapH° value of 82.9±1 kj/mol from missing citation. |
ΔfH°gas | -133.0 ± 0.26 | kcal/mol | Ccb | Lebedeva, 1964 | Value computed using ΔfHliquid° from Lebedeva, 1964 and ΔvapH° value of 19.2 kcal/mol from Baccanari, Novinski, et al., 1968. estimated uncertainty |
Phase change data
Go To: Top, Gas phase thermochemistry 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 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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 510. ± 4. | K | AVG | N/A | Average of 22 out of 24 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 289.3 ± 0.7 | K | AVG | N/A | Average of 6 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 289.66 | K | N/A | Schaake, van Miltenburg, et al., 1982 | Uncertainty assigned by TRC = 0.02 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 693.0 | K | N/A | Andereya and Chase, 1990 | Uncertainty assigned by TRC = 1. K; TRC |
Tc | 694. | K | N/A | Ambrose and Ghiassee, 1987 | Uncertainty assigned by TRC = 1.5 K; TRC |
Tc | 697.2 | K | N/A | D'Souza and Teja, 1987 | Uncertainty assigned by TRC = 3. K; Ambrose's procedure; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 28.31 | atm | N/A | Andereya and Chase, 1990 | Uncertainty assigned by TRC = 0.59 atm; TRC |
Pc | 26.65 | atm | N/A | Ambrose and Ghiassee, 1987 | Uncertainty assigned by TRC = 2.47 atm; TRC |
Pc | 25.3189 | atm | N/A | D'Souza and Teja, 1987 | Uncertainty assigned by TRC = 0.89 atm; Ambrose's procedure; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 19.4 ± 0.1 | kcal/mol | GS | Verevkin, 2000 | Based on data from 297. to 434. K.; AC |
ΔvapH° | 19.4 | kcal/mol | CGC | Chickos, Hosseini, et al., 1995 | Based on data from 353. to 393. K.; AC |
ΔvapH° | 19.8 ± 0.24 | kcal/mol | V | Kruif and Oonk, 1979 | ALS |
ΔvapH° | 19.8 ± 0.24 | kcal/mol | TE | Kruif and Oonk, 1979 | Based on data from 291. to 303. K.; AC |
ΔvapH° | 19.2 | kcal/mol | V | Baccanari, Novinski, et al., 1968 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔsubH° | 27. ± 1. | kcal/mol | TPD | Cappa, Lovejoy, et al., 2008 | AC |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
19.1 ± 0.1 | 320. | GS | Verevkin, 2000 | Based on data from 297. to 343. K.; AC |
15.9 | 432. | A,EB | Ambrose and Ghiassee, 1987, 2 | Based on data from 417. to 514. K.; AC |
20.4 | 311. | A | Stephenson and Malanowski, 1987 | Based on data from 296. to 331. K.; AC |
17.8 | 375. | A | Stephenson and Malanowski, 1987 | Based on data from 360. to 512. K.; AC |
19.1 | 290. | N/A | de Kruif, Schaake, et al., 1982 | AC |
16.7 | 407. | I | Cramer, 1943 | AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
403.3 to 479.5 | 4.24664 | 1530.446 | -150.12 | Rose, Acciarri, et al., 1957 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
5.1099 | 289.5 | Garner and Randall, 1924 | DH |
5.110 | 289.7 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
17.7 | 289.5 | Garner and Randall, 1924 | DH |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
5.1028 | 289.66 | crystaline, I | liquid | Schaake, van Miltenburg, et al., 1982, 2 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
17.62 | 289.66 | crystaline, I | liquid | Schaake, van Miltenburg, et al., 1982, 2 | DH |
References
Go To: Top, Gas phase thermochemistry data, Phase change data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
Baccanari, Novinski, et al., 1968
Baccanari, D.P.; Novinski, J.A.; Pan, Y.; Yevitz, M.M.; Swain, H.A., Jr.,
Heats of sublimation and vaporization at 25° of long chain fatty acids and methyl esters,
Trans. Faraday Soc., 1968, 64, 1201. [all data]
Lebedeva, 1964
Lebedeva, N.D.,
Heats of combustion of monocarboxylic acids,
Russ. J. Phys. Chem. (Engl. Transl.), 1964, 38, 1435-1437. [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. Thermodyn., 1982, 14, 771-8. [all data]
Andereya and Chase, 1990
Andereya, E.; Chase, J.D.,
Chem. Eng. Technol., 1990, 13, 304-12. [all data]
Ambrose and Ghiassee, 1987
Ambrose, D.; Ghiassee, N.B.,
Vapor Pressures and Critical Temperatures and Critical Pressures of Some Alkanoic Acids: C1 to C10,
J. Chem. Thermodyn., 1987, 19, 505. [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]
Verevkin, 2000
Verevkin, S.P.,
Measurement and Prediction of the Monocarboxylic Acids Thermochemical Properties,
J. Chem. Eng. Data, 2000, 45, 5, 953-960, https://doi.org/10.1021/je990282m
. [all data]
Chickos, Hosseini, et al., 1995
Chickos, James S.; Hosseini, Sarah; Hesse, Donald G.,
Determination of vaporization enthalpies of simple organic molecules by correlations of changes in gas chromatographic net retention times,
Thermochimica Acta, 1995, 249, 41-62, https://doi.org/10.1016/0040-6031(95)90670-3
. [all data]
Kruif and Oonk, 1979
Kruif, C.G.; Oonk, H.A.J.,
Enthalpies of vaporization and vapour pressures of seven aliphatic carboxylic acids,
J. Chem. Thermodyn., 1979, 11, 287-290. [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]
Ambrose and Ghiassee, 1987, 2
Ambrose, D.; Ghiassee, N.B.,
Vapour pressures and critical temperatures and critical pressures of some alkanoic acids: C1 to C10,
The Journal of Chemical Thermodynamics, 1987, 19, 5, 505-519, https://doi.org/10.1016/0021-9614(87)90147-9
. [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]
Rose, Acciarri, et al., 1957
Rose, Arthur.; Acciarri, Jerry A.; Johnson, R. Curtis.; Sanders, W.W.,
Automatic Computation of Antoine Equation 31 Constants---Caproic and Caprylic Acids and Methyl Esters,
Ind. Eng. Chem., 1957, 49, 1, 104-109, https://doi.org/10.1021/ie50565a036
. [all data]
Garner and Randall, 1924
Garner, W.E.; Randall, F.C.,
Alternation in the heats of crystallization of the normal monobasic fatty acids. Part I.,
J. Chem. Soc., 1924, 125, 881-896. [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]
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. Thermodynam., 1982, 14, 771-778. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, References
- Symbols used in this document:
Pc Critical pressure Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature 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 at standard conditions ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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