Pentane, 2,2,4-trimethyl-
- Formula: C8H18
- Molecular weight: 114.2285
- IUPAC Standard InChIKey: NHTMVDHEPJAVLT-UHFFFAOYSA-N
- CAS Registry Number: 540-84-1
- 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: Isooctane; Isobutyltrimethylmethane; 2,2,4-Trimethylpentane; (CH3)2CHCH2C(CH3)3; Isobutyltrimethylethane; UN 1262
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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:
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 | -53.57 ± 0.32 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
31.209 | 200. | Scott D.W., 1974 | Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, 2, Scott D.W., 1974]. This approach gives a good agreement with experimental data available for alkanes. However, large uncertainties could be expected at high temperatures.; GT |
41.580 | 273.15 | ||
45.03 ± 0.1 | 298.15 | ||
45.280 | 300. | ||
58.461 | 400. | ||
70.129 | 500. | ||
80.201 | 600. | ||
88.901 | 700. | ||
96.401 | 800. | ||
102.90 | 900. | ||
108.70 | 1000. | ||
113.70 | 1100. | ||
118.20 | 1200. | ||
122.00 | 1300. | ||
126.00 | 1400. | ||
129.00 | 1500. |
Condensed 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:
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 |
---|---|---|---|---|---|
ΔfH°liquid | -61.98 ± 0.32 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -1305.29 ± 0.30 | kcal/mol | Ccb | Prosen and Rossini, 1945 | Corresponding ΔfHºliquid = -61.95 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 78.401 | cal/mol*K | N/A | Pitzer K.S., 1940 | DH |
S°liquid | 75.19 | cal/mol*K | N/A | Parks, Huffman, et al., 1930 | Extrapolation below 90 K, 66.53 J/mol*K.; DH |
Constant pressure heat capacity of liquid
Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
57.957 | 298.15 | Costas, Huu, et al., 1988 | DH |
57.957 | 298.15 | Perez-Casas, Aicart, et al., 1988 | DH |
57.292 | 298.15 | Shiohama, Ogawa, et al., 1988 | DH |
56.848 | 293.15 | Kalali, Kohler, et al., 1987 | T = 293.15, 313.15 K.; DH |
57.0915 | 298.15 | Fortier and Benson, 1976 | Average of three values.; DH |
56.84 | 298.15 | Rajagopal and Subrahmanyam, 1974 | T = 298.15 to 323.15 K.; DH |
56.84 | 298.15 | Subrahmanyam and Rajagopal, 1973 | T = 298 to 323 K.; DH |
55.86 | 300. | Auerbach, Sage, et al., 1950 | T = 300 to 366 K. Cp given as 0.4980 Btu/lb*R at 80 F.; DH |
57.020 | 298.15 | Osborne and Ginnings, 1947 | T = 283 to 318 K.; DH |
57.600 | 301.9 | Pitzer K.S., 1940 | T = 15 to 318 K. Value is unsmoothed experimental datum.; DH |
55.90 | 295.2 | Parks, Huffman, et al., 1930 | T = 88 to 295 K. Value is unsmoothed experimental datum.; DH |
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: C8H16 + H2 = C8H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -25.5 | kcal/mol | Chyd | Turner, Nettleton, et al., 1958 | liquid phase; solvent: Acetic acid |
ΔrH° | -26.99 ± 0.06 | kcal/mol | Chyd | Dolliver, Gresham, et al., 1937 | gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -27.24 ± 0.06 kcal/mol; At 355 °K |
ΔrH° | -28.58 ± 0.80 | kcal/mol | Chyd | Crawford and Parks, 1936 | liquid phase |
By formula: C8H16 + H2 = C8H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -26.8 | kcal/mol | Chyd | Turner, Nettleton, et al., 1958 | liquid phase; solvent: Acetic acid |
ΔrH° | -28.39 | kcal/mol | Chyd | Dolliver, Gresham, et al., 1937 | gas phase; At 355 °K |
By formula: C8H18 = C8H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -2.24 ± 0.25 | kcal/mol | Ciso | Prosen and Rossini, 1945, 2 | liquid phase; Calculated from ΔHc |
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:
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 9.89 ± 0.03 | eV | N/A | N/A | L |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
9.91 | PE | Al-Joboury and Turner, 1964 | RDSH |
9.86 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, 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]
Scott D.W., 1974
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]
Scott D.W., 1974, 2
Scott D.W.,
Correlation of the chemical thermodynamic properties of alkane hydrocarbons,
J. Chem. Phys., 1974, 60, 3144-3165. [all data]
Pitzer K.S., 1940
Pitzer K.S.,
The thermodynamics of n-heptane and 2,2,4-trimethylpentane, including heat capacities, heats of fusion and vaporization and entropies,
J. Am. Chem. Soc., 1940, 62, 1224-1227. [all data]
Parks, Huffman, et al., 1930
Parks, G.S.; Huffman, H.M.; Thomas, S.B.,
Thermal data on organic compounds. VI. The heat capacities, entropies and free energies of some saturated, non-benzenoid hydrocarbons,
J. Am. Chem. Soc., 1930, 52, 1032-1041. [all data]
Costas, Huu, et al., 1988
Costas, M.; Huu, V.T.; Patterson, D.; Caceres-Alonso, M.; Tardajos, G.; Aicart, E.,
Liquid structure and second-order mixing functions for l-chloronaphthalene with linear and branched alkanes, J. Chem. Soc.,
Faraday Trans., 1988, 1 84(5), 1603-1616. [all data]
Perez-Casas, Aicart, et al., 1988
Perez-Casas, S.; Aicart, E.; Trojo, L.M.; Costas, M.,
Excess heat capacity. Chlorobenzene-2,2,4,4,6,8,8-heptamethylnonane, Int. Data Ser.,
Sel. Data Mixtures, 1988, (2)A, 123. [all data]
Shiohama, Ogawa, et al., 1988
Shiohama, Y.; Ogawa, H.; Murakami, S.; Fujihara, I.,
Excess molar isobaric heat capacities and isentropic compressibilities of (cis- or trans-decalin + benzene or toluene or iso-octane or n-heptane) at 298.15 K,
J. Chem. Thermodynam., 1988, 20, 1183-1189. [all data]
Kalali, Kohler, et al., 1987
Kalali, H.; Kohler, F.; Svejda, P.,
Excess properties of the mixture bis(2-dichlorethyl)ether (chlorex) + 2,2,4-trimethylpentane (isooctane),
Monatsh. Chem., 1987, 118, 1-18. [all data]
Fortier and Benson, 1976
Fortier, J.-L.; Benson, G.C.,
Excess heat capacities of binary liquid mixtures determined with a Picker flow calorimeter,
J. Chem. Thermodynam., 1976, 8, 411-423. [all data]
Rajagopal and Subrahmanyam, 1974
Rajagopal, E.; Subrahmanyam, S.V.,
Excess function of VE,(dVE/dp)T, and CpE of isooctane + benzene and + toluene,
J. Chem. Thermodynam., 1974, 6, 873-876. [all data]
Subrahmanyam and Rajagopal, 1973
Subrahmanyam, S.V.; Rajagopal, E.,
Excess thermodynamic functions of the systems isooctane + carbon tetrachloride and isooctane + cyclohexane,
Z. Phys. Chem. [NF], 1973, 85, 256-268. [all data]
Auerbach, Sage, et al., 1950
Auerbach, C.E.; Sage, B.H.; Lacey, W.N.,
Isobaric heat capacities at bubble point,
Ind. Eng. Chem., 1950, 42, 110-113. [all data]
Osborne and Ginnings, 1947
Osborne, N.S.; Ginnings, D.C.,
Measurements of heat of vaporization and heat capacity of a number of hydrocarbons,
J. Res. NBS, 1947, 39, 453-477. [all data]
Turner, Nettleton, et al., 1958
Turner, R.B.; Nettleton, J.E.; Perelman,
Heats of Hydrogenation. VI. Heats of hydrogenation of some substituted ethylenes,
J. Am. Chem. Soc., 1958, 80, 1430-1433. [all data]
Dolliver, Gresham, et al., 1937
Dolliver, M.a.; Gresham, T.L.; Kistiakowsky, G.B.; Vaughan, W.E.,
Heats of organic reactions. V. Heats of hydrogenation of various hydrocarbons,
J. Am. Chem. Soc., 1937, 59, 831-841. [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]
Crawford and Parks, 1936
Crawford, B.L., Jr.; Parks, G.S.,
The heat of hydrogenation of diisobutylene,
J. Am. Chem. Soc., 1936, 58, 373. [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]
Al-Joboury and Turner, 1964
Al-Joboury, M.I.; Turner, D.W.,
Molecular photoelectron spectroscopy. Part II. A summary of ionization potentials,
J. Chem. Soc., 1964, 4434. [all data]
Watanabe, Nakayama, et al., 1962
Watanabe, K.; Nakayama, T.; Mottl, J.,
Ionization potentials of some molecules,
J. Quant. Spectry. Radiative Transfer, 1962, 2, 369. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Cp,liquid Constant pressure heat capacity of liquid IE (evaluated) Recommended ionization energy S°liquid Entropy of liquid at standard conditions ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔrH° Enthalpy of reaction at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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