Octane

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Gas phase 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 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-49.88kcal/molN/AGood, 1972Value 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-49.82 ± 0.16kcal/molCcbProsen and Rossini, 1945see Prosen and Rossini, 1944; ALS
Quantity Value Units Method Reference Comment
S°gas111.63 ± 0.22cal/mol*KN/AScott D.W., 1974This 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 (cal/mol*K) Temperature (K) Reference Comment
55.63 ± 0.11385.65Hossenlopp I.A., 1981Please also see Barrow G.M., 1951.; GT
57.11 ± 0.11398.15
58.000405.7
59.89 ± 0.12423.15
62.86 ± 0.13448.15
64.699462.5
65.69 ± 0.13473.15
68.35 ± 0.14498.15
70.600522.7
70.98 ± 0.14523.15

Constant pressure heat capacity of gas

Cp,gas (cal/mol*K) Temperature (K) Reference Comment
34.601200.Scott D.W., 1974, 2Recommended 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
41.991273.15
44.88 ± 0.1298.15
45.100300.
57.299400.
68.549500.
78.100600.
86.099700.
92.801800.
98.401900.
103.101000.
107.201100.
110.701200.
114.001300.
117.001400.
119.001500.

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

1-Octene + Hydrogen = Octane

By formula: C8H16 + H2 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-30. ± 2.kcal/molAVGN/AAverage of 7 values; Individual data points

Hydrogen + 4-Octene, (Z)- = Octane

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-28.25 ± 0.1kcal/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane
ΔrH°-28.62 ± 0.52kcal/molChydRogers and Siddiqui, 1975liquid phase; solvent: n-Hexane
ΔrH°-27.39 ± 0.14kcal/molChydTurner, Jarrett, et al., 1973liquid phase; solvent: Acetic acid

2Hydrogen + 4-Octyne = Octane

By formula: 2H2 + C8H14 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-64.22 ± 0.26kcal/molChydRogers, Dagdagan, et al., 1979liquid phase; solvent: Hexane
ΔrH°-62.80 ± 0.16kcal/molChydTurner, Jarrett, et al., 1973liquid phase; solvent: Acetic acid
ΔrH°-62.8kcal/molChydSicher, Svoboda, et al., 1966liquid phase; solvent: Acetic acid

2Hydrogen + 1-Octyne = Octane

By formula: 2H2 + C8H14 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-69.55 ± 0.47kcal/molChydMolnar, Rachford, et al., 1984liquid phase; solvent: Dioxane
ΔrH°-69.15 ± 0.65kcal/molChydRogers, Dagdagan, et al., 1979liquid phase; solvent: Hexane

Octane = Pentane, 3-ethyl-3-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-0.73 ± 0.21kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Heptane, 2-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-1.25 ± 0.22kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Heptane, 3-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-0.61 ± 0.19kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Heptane, 4-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-0.44 ± 0.19kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Hexane, 3-ethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-0.14 ± 0.17kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Hexane, 2,2-dimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-2.89 ± 0.16kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Hexane, 2,3-dimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-0.67 ± 0.28kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Hexane, 2,4-dimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-1.73 ± 0.18kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Hexane, 2,5-dimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-2.53 ± 0.28kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Hexane, 3,3-dimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-1.85 ± 0.17kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Hexane, 3,4-dimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-0.49 ± 0.29kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Pentane, 2,2,3-trimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-1.70 ± 0.28kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Pentane, 2,2,4-trimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-2.24 ± 0.25kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Pentane, 2,3,3-trimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-0.89 ± 0.26kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Pentane, 2,3,4-trimethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-1.25 ± 0.32kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Butane, 2,2,3,3-tetramethyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-4.50 ± 0.38kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Octane = Pentane, 3-ethyl-2-methyl-

By formula: C8H18 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°0.05 ± 0.22kcal/molCisoProsen and Rossini, 1945, 2liquid phase; Calculated from ΔHc

Hydrogen + 2-Octene, (E)- = Octane

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-27.6 ± 0.2kcal/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane

Hydrogen + 3-Octene, (Z)- = Octane

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-28.15 ± 0.1kcal/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane

Hydrogen + 4-Octene, (E)- = Octane

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-27.49 ± 0.1kcal/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane

Hydrogen + 3-Octene, (E)- = Octane

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-27.68 ± 0.1kcal/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane

2Hydrogen + 3-Octyne = Octane

By formula: 2H2 + C8H14 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-64.80 ± 0.19kcal/molChydRogers, Dagdagan, et al., 1979liquid phase; solvent: Hexane

Hydrogen + 2-Octene, (Z)- = Octane

By formula: H2 + C8H16 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-28.54 ± 0.26kcal/molChydRogers, Dejroongruang, et al., 1992liquid phase; solvent: Cyclohexane

2Hydrogen + 2-Octyne = Octane

By formula: 2H2 + C8H14 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-65.10 ± 0.11kcal/molChydRogers, Dagdagan, et al., 1979liquid phase; solvent: Hexane

4Hydrogen + 1,7-Octadiyne = Octane

By formula: 4H2 + C8H10 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-139.7 ± 1.2kcal/molChydFlitcroft, Skinner, et al., 1957liquid phase

3Hydrogen + 1-Octen-3-yne = Octane

By formula: 3H2 + C8H12 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-93.4 ± 1.5kcal/molChydFlitcroft and Skinner, 1958liquid phase

4Hydrogen + Octa-1,2,6,7-teraene = Octane

By formula: 4H2 + C8H10 = C8H18

Quantity Value Units Method Reference Comment
ΔrH°-138.0kcal/molChydRoth, Scholz, et al., 1982liquid phase

Octane = Hydrogen + 2-Octene, (E)-

By formula: C8H18 = H2 + C8H16

Quantity Value Units Method Reference Comment
ΔrH°27.192kcal/molEqkEliseev, 1986liquid phase

Octane = Hydrogen + 3-Octene, (Z)-

By formula: C8H18 = H2 + C8H16

Quantity Value Units Method Reference Comment
ΔrH°28.260kcal/molEqkEliseev, 1986liquid phase

Octane = Hydrogen + 3-Octene, (E)-

By formula: C8H18 = H2 + C8H16

Quantity Value Units Method Reference Comment
ΔrH°27.261kcal/molEqkEliseev, 1986liquid phase

Octane = Hydrogen + 4-Octene, (E)-

By formula: C8H18 = H2 + C8H16

Quantity Value Units Method Reference Comment
ΔrH°27.261kcal/molEqkEliseev, 1986liquid phase

Octane = Hydrogen + 2-Octene, (Z)-

By formula: C8H18 = H2 + C8H16

Quantity Value Units Method Reference Comment
ΔrH°28.191kcal/molEqkEliseev, 1986liquid phase

Octane = Hydrogen + 4-Octene, (Z)-

By formula: C8H18 = H2 + C8H16

Quantity Value Units Method Reference Comment
ΔrH°28.260kcal/molEqkEliseev, 1986liquid phase

Octane = 1-Octene + Hydrogen

By formula: C8H18 = C8H16 + H2

Quantity Value Units Method Reference Comment
ΔrH°30.000kcal/molEqkEliseev, 1986liquid phase

Gas phase ion energetics 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 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

Quantity Value Units Method Reference Comment
IE (evaluated)9.80 ± 0.15eVN/AN/AL

Ionization energy determinations

IE (eV) Method Reference Comment
10.01ESTLuo and Pacey, 1992LL
9.80 ± 0.10EVALLias, 1982LBLHLM
9.71 ± 0.15EQMautner(Meot-Ner), Sieck, et al., 1981LLK
9.79EQLias, Ausloos, et al., 1976LLK
10.25EIPotzinger and Bunau, 1969RDSH

Appearance energy determinations

Ion AE (eV) Other Products MethodReferenceComment
C2H5+13.44?EIPotzinger and Bunau, 1969RDSH
C3H7+11.89?EIPotzinger and Bunau, 1969RDSH
C4H8+11.19 ± 0.07C4H10PISteiner, Giese, et al., 1961RDSH
C4H9+11.12n-C4H9?EIPotzinger and Bunau, 1969RDSH
C4H9+11.40 ± 0.07n-C4H9?PISteiner, Giese, et al., 1961RDSH
C5H10+11.08 ± 0.03C3H8PISteiner, Giese, et al., 1961RDSH
C5H11+11.03C3H7EIPotzinger and Bunau, 1969RDSH
C5H11+11.22 ± 0.085C3H7PISteiner, Giese, et al., 1961RDSH
C6H12+10.29C2H6EILewis and Hamill, 1970RDSH
C6H12+10.81 ± 0.03C2H6PISteiner, Giese, et al., 1961RDSH
C6H13+10.91 ± 0.035C2H5PISteiner, Giese, et al., 1961RDSH
C7H15+~10.90 ± 0.10CH3PISteiner, Giese, et al., 1961RDSH

IR Spectrum

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Data compiled by: Tanya L. Myers, Russell G. Tonkyn, Ashley M. Oeck, Tyler O. Danby, John S. Loring, Matthew S. Taubman, Stephen W. Sharpe, Jerome C. Birnbaum, and Timothy J. Johnson

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

References

Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics 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]

Luo and Pacey, 1992
Luo, Y.-R.; Pacey, P.D., Effects of alkyl substitution on ionization energies of alkanes and haloalkanes and on heats of formation of their molecular cations. Part 2. Alkanes and chloro-, bromo- and iodoalkanes, Int. J. Mass Spectrom. Ion Processes, 1992, 112, 63. [all data]

Lias, 1982
Lias, S.G., Thermochemical information from ion-molecule rate constants, Ion Cyclotron Reson. Spectrom. 1982, 1982, 409. [all data]

Mautner(Meot-Ner), Sieck, et al., 1981
Mautner(Meot-Ner), M.; Sieck, L.W.; Ausloos, P., Ionization of normal alkanes: Enthalpy, entropy, structural, and isotope effects, J. Am. Chem. Soc., 1981, 103, 5342. [all data]

Lias, Ausloos, et al., 1976
Lias, S.G.; Ausloos, P.; Horvath, Z., Charge transfer reactions in alkane and cycloalkane systems. Estimated ionization potentials, Int. J. Chem. Kinet., 1976, 8, 725. [all data]

Potzinger and Bunau, 1969
Potzinger, P.; Bunau, G.v., Empirische Beruksichtigung von Uberschussenergien bei der Auftrittspotentialbestimmung, Ber. Bunsen-Ges. Phys. Chem., 1969, 73, 466. [all data]

Steiner, Giese, et al., 1961
Steiner, B.; Giese, C.F.; Inghram, M.G., Photoionization of alkanes. Dissociation of excited molecular ions, J. Chem. Phys., 1961, 34, 189. [all data]

Lewis and Hamill, 1970
Lewis, D.; Hamill, W.H., Excited states of neutral molecular fragments from appearance potentials by electron impact in a mass spectrometer, J. Chem. Phys., 1970, 52, 6348. [all data]

Notes

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