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
- IUPAC Standard InChIKey: TVMXDCGIABBOFY-UHFFFAOYSA-N
- 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:
- Other names: n-Octane; n-C8H18; Oktan; Oktanen; Ottani; UN 1262
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Gas phase thermochemistry data
Go To: Top, Reaction thermochemistry data, IR Spectrum, 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
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | -208.7 | kJ/mol | N/A | Good, 1972 | Value computed using ΔfHliquid° value of -250.3±1.8 kj/mol from Good, 1972 and ΔvapH° value of 41.6 kj/mol from Prosen and Rossini, 1945.; DRB |
| ΔfH°gas | -208.4 ± 0.67 | kJ/mol | Ccb | Prosen and Rossini, 1945 | see Prosen and Rossini, 1944; ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas | 467.06 ± 0.92 | J/mol*K | N/A | Scott D.W., 1974 | This reference does not contain the original experimental data. Experimental entropy value is based on the results [ Messerly J.F., 1967] for S(liquid).; GT |
Constant pressure heat capacity of gas
| Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 232.74 ± 0.47 | 385.65 | Hossenlopp I.A., 1981 | Please also see Barrow G.M., 1951.; GT |
| 238.95 ± 0.48 | 398.15 | ||
| 242.67 | 405.7 | ||
| 250.59 ± 0.50 | 423.15 | ||
| 263.02 ± 0.53 | 448.15 | ||
| 270.70 | 462.5 | ||
| 274.84 ± 0.55 | 473.15 | ||
| 285.98 ± 0.57 | 498.15 | ||
| 295.39 | 522.7 | ||
| 297.00 ± 0.59 | 523.15 |
Constant pressure heat capacity of gas
| Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 144.77 | 200. | Scott D.W., 1974, 2 | Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, Scott D.W., 1974, 2]. This approach gives a better agreement with experimental data than the statistical thermodynamics calculation [ Pitzer K.S., 1944, Pitzer K.S., 1946].; GT |
| 175.69 | 273.15 | ||
| 187.8 ± 0.4 | 298.15 | ||
| 188.70 | 300. | ||
| 239.74 | 400. | ||
| 286.81 | 500. | ||
| 326.77 | 600. | ||
| 360.24 | 700. | ||
| 388.28 | 800. | ||
| 411.71 | 900. | ||
| 431.37 | 1000. | ||
| 448.52 | 1100. | ||
| 463.17 | 1200. | ||
| 476.98 | 1300. | ||
| 489.53 | 1400. | ||
| 497.90 | 1500. |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, IR Spectrum, 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
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: C8H16 + H2 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -125. ± 6. | kJ/mol | AVG | N/A | Average of 7 values; Individual data points |
+
=
By formula: H2 + C8H16 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -118.2 ± 0.4 | kJ/mol | Chyd | Rogers, Dejroongruang, et al., 1992 | liquid phase; solvent: Cyclohexane |
| ΔrH° | -119.7 ± 2.2 | kJ/mol | Chyd | Rogers and Siddiqui, 1975 | liquid phase; solvent: n-Hexane |
| ΔrH° | -114.6 ± 0.59 | kJ/mol | Chyd | Turner, Jarrett, et al., 1973 | liquid phase; solvent: Acetic acid |
2 +
=
By formula: 2H2 + C8H14 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -268.7 ± 1.1 | kJ/mol | Chyd | Rogers, Dagdagan, et al., 1979 | liquid phase; solvent: Hexane |
| ΔrH° | -262.8 ± 0.67 | kJ/mol | Chyd | Turner, Jarrett, et al., 1973 | liquid phase; solvent: Acetic acid |
| ΔrH° | -263. | kJ/mol | Chyd | Sicher, Svoboda, et al., 1966 | liquid phase; solvent: Acetic acid |
2 +
=
By formula: 2H2 + C8H14 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -291.0 ± 2.0 | kJ/mol | Chyd | Molnar, Rachford, et al., 1984 | liquid phase; solvent: Dioxane |
| ΔrH° | -289.3 ± 2.7 | kJ/mol | Chyd | Rogers, Dagdagan, et al., 1979 | liquid phase; solvent: Hexane |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -3.1 ± 0.88 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -5.23 ± 0.92 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -2.6 ± 0.79 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -1.8 ± 0.79 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -0.59 ± 0.71 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -12.1 ± 0.67 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -2.8 ± 1.2 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -7.24 ± 0.75 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -10.6 ± 1.2 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -7.74 ± 0.71 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -2.1 ± 1.2 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -7.1 ± 1.2 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -9.4 ± 1.0 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -3.7 ± 1.1 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -5.2 ± 1.3 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -18.8 ± 1.6 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
=
By formula: C8H18 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 0.2 ± 0.92 | kJ/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
+
=
By formula: H2 + C8H16 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -115.5 ± 0.7 | kJ/mol | Chyd | Rogers, Dejroongruang, et al., 1992 | liquid phase; solvent: Cyclohexane |
+
=
By formula: H2 + C8H16 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -117.8 ± 0.4 | kJ/mol | Chyd | Rogers, Dejroongruang, et al., 1992 | liquid phase; solvent: Cyclohexane |
+
=
By formula: H2 + C8H16 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -115.0 ± 0.4 | kJ/mol | Chyd | Rogers, Dejroongruang, et al., 1992 | liquid phase; solvent: Cyclohexane |
+
=
By formula: H2 + C8H16 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -115.8 ± 0.4 | kJ/mol | Chyd | Rogers, Dejroongruang, et al., 1992 | liquid phase; solvent: Cyclohexane |
2 +
=
By formula: 2H2 + C8H14 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -271.1 ± 0.79 | kJ/mol | Chyd | Rogers, Dagdagan, et al., 1979 | liquid phase; solvent: Hexane |
+
=
By formula: H2 + C8H16 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -119.4 ± 1.1 | kJ/mol | Chyd | Rogers, Dejroongruang, et al., 1992 | liquid phase; solvent: Cyclohexane |
2 +
=
By formula: 2H2 + C8H14 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -272.4 ± 0.46 | kJ/mol | Chyd | Rogers, Dagdagan, et al., 1979 | liquid phase; solvent: Hexane |
4 +
=
By formula: 4H2 + C8H10 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -584.5 ± 5.0 | kJ/mol | Chyd | Flitcroft, Skinner, et al., 1957 | liquid phase |
3 +
=
By formula: 3H2 + C8H12 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -391. ± 6.3 | kJ/mol | Chyd | Flitcroft and Skinner, 1958 | liquid phase |
4 +
=
By formula: 4H2 + C8H10 = C8H18
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -577.4 | kJ/mol | Chyd | Roth, Scholz, et al., 1982 | liquid phase |
=
+
By formula: C8H18 = H2 + C8H16
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 113.77 | kJ/mol | Eqk | Eliseev, 1986 | liquid phase |
=
+
By formula: C8H18 = H2 + C8H16
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 118.24 | kJ/mol | Eqk | Eliseev, 1986 | liquid phase |
=
+
By formula: C8H18 = H2 + C8H16
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 114.06 | kJ/mol | Eqk | Eliseev, 1986 | liquid phase |
=
+
By formula: C8H18 = H2 + C8H16
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 114.06 | kJ/mol | Eqk | Eliseev, 1986 | liquid phase |
=
+
By formula: C8H18 = H2 + C8H16
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 117.95 | kJ/mol | Eqk | Eliseev, 1986 | liquid phase |
=
+
By formula: C8H18 = H2 + C8H16
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 118.24 | kJ/mol | Eqk | Eliseev, 1986 | liquid phase |
=
+
By formula: C8H18 = C8H16 + H2
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 125.52 | kJ/mol | Eqk | Eliseev, 1986 | liquid phase |
IR Spectrum
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, References, Notes
Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director
References
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, IR Spectrum, 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]
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]
Prosen and Rossini, 1944
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]
Scott D.W., 1974
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
Messerly J.F.,
Low-temperature thermal data for n-pentane, n-heptadecane, and n-octadecane. Revised thermodynamic functions for the n-alkanes, C5-C18,
J. Chem. Eng. Data, 1967, 12, 338-346. [all data]
Hossenlopp I.A., 1981
Hossenlopp I.A.,
Vapor heat capacities and enthalpies of vaporization of five alkane hydrocarbons,
J. Chem. Thermodyn., 1981, 13, 415-421. [all data]
Barrow G.M., 1951
Barrow G.M.,
Experimental vapor heat capacities and heats of vaporization of seven octanes,
J. Am. Chem. Soc., 1951, 73, 1824-1826. [all data]
Scott D.W., 1974, 2
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]
Pitzer K.S., 1944
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]
Rogers, Dejroongruang, et al., 1992
Rogers, D.W.; Dejroongruang, K.; Samuel, S.D.; Fang, W.; Zhao, Y.,
Enthalpies of hydrogenation of the octenes and the methylheptenes,
J. Chem. Thermodyn., 1992, 24, 561-565. [all data]
Rogers and Siddiqui, 1975
Rogers, D.W.; Siddiqui, N.A.,
Heats of hydrogenation of large molecules. I. Esters of unsaturated fatty acids,
J. Phys. Chem., 1975, 79, 574-577. [all data]
Turner, Jarrett, et al., 1973
Turner, R.B.; Jarrett, A.D.; Goebel, P.; Mallon, B.J.,
Heats of hydrogenation. 9. Cyclic acetylenes and some miscellaneous olefins,
J. Am. Chem. Soc., 1973, 95, 790-792. [all data]
Rogers, Dagdagan, et al., 1979
Rogers, D.W.; Dagdagan, O.A.; Allinger, N.L.,
Heats of hydrogenation and formation of linear alkynes and a molecular mechanics interpretation,
J. Am. Chem. Soc., 1979, 101, 671-676. [all data]
Sicher, Svoboda, et al., 1966
Sicher, J.; Svoboda, M.; Zavada, J.; Turner, R.B.; Goebel, P.,
Sterochemical studies - XXXVI. An approach to conformational analysis of medium ring compounds. Unsaturated ten-membered ring derivates,
Tetrahedron, 1966, 22, 659-671. [all data]
Molnar, Rachford, et al., 1984
Molnar, A.; Rachford, R.; Smith, G.V.; Liu, R.,
Heats of hydrogenation by a simple and rapid flow calorimetric method,
Appl. Catal., 1984, 9, 219-223. [all data]
Prosen and Rossini, 1945, 2
Prosen, E.J.; Rossini, F.D.,
Heats of isomerization of the 18 octanes,
J. Res. NBS, 1945, 34, 163-174. [all data]
Flitcroft, Skinner, et al., 1957
Flitcroft, T.; Skinner, H.A.; Whiting, M.C.,
Heats of hydrogenation Part 1.-Dodeca-3:9 and -5:7 Diynes,
Trans. Faraday Soc., 1957, 53, 784-790. [all data]
Flitcroft and Skinner, 1958
Flitcroft, T.L.; Skinner, H.A.,
Heats of hydrogenation Part 2.-Acetylene derivatives,
Trans. Faraday Soc., 1958, 54, 47-53. [all data]
Roth, Scholz, et al., 1982
Roth, W.R.; Scholz, B.P.; Breuckmann, R.; Jelich, K.; Lennartz, H.W.,
Thermolysis of 1,2,6,7-octatetraene,
Chem. Ber., 1982, 115, 1934-1946. [all data]
Eliseev, 1986
Eliseev, N.A.,
Thermodynamic calculation of the equilibrium composition of isomeric octenes in dehydrogenation of n-octane,
Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol., 1986, 29, 26-29. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, IR Spectrum, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas S°gas Entropy of gas at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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