Hexane, 2,5-dimethyl-
- Formula: C8H18
- Molecular weight: 114.2285
- IUPAC Standard InChIKey: UWNADWZGEHDQAB-UHFFFAOYSA-N
- CAS Registry Number: 592-13-2
- 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: Biisobutyl; 2,5-Dimethylhexane
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Condensed phase thermochemistry data
Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics 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:
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 | -260.5 ± 1.5 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -5460.1 ± 1.4 | kJ/mol | Ccb | Prosen and Rossini, 1945 | Corresponding ΔfHºliquid = -260.4 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -5435.9 | kJ/mol | Ccb | Fajans, 1920 | Corresponding ΔfHºliquid = -285. kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -5266.2 | kJ/mol | Ccb | Richards and Jesse, 1910 | At 293 K; Corresponding ΔfHºliquid = -454.4 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Constant pressure heat capacity of liquid
Cp,liquid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
249.20 | 298.15 | Osborne and Ginnings, 1947 | T = 278 to 318 K.; DH |
Phase change data
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics 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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 382.1 ± 0.9 | K | AVG | N/A | Average of 39 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 182. ± 2. | K | AVG | N/A | Average of 19 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 181.960 | K | N/A | Anonymous, 1957 | Uncertainty assigned by TRC = 0.04 K; TRC |
Ttriple | 181.970 | K | N/A | Anonymous, 1957 | Uncertainty assigned by TRC = 0.02 K; TRC |
Ttriple | 181.960 | K | N/A | Anonymous, 1957 | Uncertainty assigned by TRC = 0.04 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 550.0 ± 0.5 | K | N/A | Daubert, 1996 | |
Tc | 549.99 | K | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4 K; TRC |
Tc | 550.0 | K | N/A | Young, 1910 | Uncertainty assigned by TRC = 0.5 K; TRC |
Tc | 544.0 | K | N/A | Pawlewski, 1883 | Uncertainty assigned by TRC = 8. K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 24.9 ± 0.2 | bar | N/A | Daubert, 1996 | |
Pc | 24.867 | bar | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4053 bar; TRC |
Pc | 24.878 | bar | N/A | Young, 1910 | Uncertainty assigned by TRC = 0.20 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.482 | l/mol | N/A | Daubert, 1996 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.07 ± 0.02 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.07 | mol/l | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.04 mol/l; TRC |
ρc | 2.071 | mol/l | N/A | Young, 1910 | Uncertainty assigned by TRC = 0.02 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 37.92 | kJ/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 37.9 | kJ/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 37.9 ± 0.1 | kJ/mol | C | Osborne and Ginnings, 1947, 2 | AC |
ΔvapH° | 37.85 | kJ/mol | C | Osborne and Ginnings, 1947 | ALS |
ΔvapH° | 32.0 | kJ/mol | V | Fajans, 1920 | ALS |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
32.54 | 382.3 | N/A | Majer and Svoboda, 1985 | |
36.9 | 322. | A,MM | Stephenson and Malanowski, 1987 | Based on data from 307. to 383. K. See also Willingham, Taylor, et al., 1945.; AC |
41.1 | 261. | N/A | Stull, 1947 | Based on data from 246. to 382. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
246.5 to 382.3 | 3.98021 | 1284.664 | -59.032 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
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: 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: C8H16 + H2 = C8H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -120.0 ± 0.08 | kJ/mol | Chyd | Turner, Jarrett, et al., 1973 | liquid phase; solvent: Acetic acid |
By formula: H2 + C8H16 = C8H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -112.2 ± 0.2 | kJ/mol | Chyd | Turner, Jarrett, et al., 1973 | liquid phase; solvent: Acetic acid |
By formula: 3H2 + C8H12 = C8H18
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -318. ± 0.4 | kJ/mol | Chyd | Roth, Adamczak, et al., 1991 | liquid 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 compiled by: Sharon G. Lias and Joel F. Liebman
Ionization energy determinations
IE (eV) | Method | Reference |
---|---|---|
9.76 | EST | Luo and Pacey, 1992 |
References
Go To: Top, Condensed phase thermochemistry data, Phase change 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]
Fajans, 1920
Fajans, K.,
Die Energie der Atombindungen im Diamanten und in aliphatischen Kohlenwasserstoffen,
Ber., 1920, 53, 643-665. [all data]
Richards and Jesse, 1910
Richards, T.W.; Jesse, R.H., Jr.,
The heats of combustion of the octanes and xylenes,
J. Am. Chem. Soc., 1910, 32, 268-298. [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]
Anonymous, 1957
Anonymous, R.,
, Am. Pet. Inst. Res. Proj. 6, Carnegie-Mellon Univ., 1957. [all data]
Daubert, 1996
Daubert, T.E.,
Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes,
J. Chem. Eng. Data, 1996, 41, 365-372. [all data]
McMicking and Kay, 1965
McMicking, J.H.; Kay, W.B.,
Vapor Pressures and Saturated Liquid and Vapor Densities of The Isomeric Heptanes and Isomeric Octanes,
Proc., Am. Pet. Inst., Sect. 3, 1965, 45, 75-90. [all data]
Young, 1910
Young, S.,
The Internal Heat of Vaporization constants of thirty pure substances,
Sci. Proc. R. Dublin Soc., 1910, 12, 374. [all data]
Pawlewski, 1883
Pawlewski, B.,
Critical temperatures of some liquids,
Ber. Dtsch. Chem. Ges., 1883, 16, 2633-36. [all data]
Majer and Svoboda, 1985
Majer, V.; Svoboda, V.,
Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]
Reid, 1972
Reid, Robert C.,
Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00,
AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637
. [all data]
Osborne and Ginnings, 1947, 2
Osborne, Nathan S.; Ginnings, Defoe C.,
Measurements of heat of vaporization and heat capacity of a number of hydrocarbons,
J. RES. NATL. BUR. STAN., 1947, 39, 5, 453-17, https://doi.org/10.6028/jres.039.031
. [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]
Willingham, Taylor, et al., 1945
Willingham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D.,
Vapor pressures and boiling points of some paraffin, alkylcyclopentane, alkylcyclohexane, and alkylbenzene hydrocarbons,
J. RES. NATL. BUR. STAN., 1945, 35, 3, 219-17, https://doi.org/10.6028/jres.035.009
. [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]
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]
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]
Roth, Adamczak, et al., 1991
Roth, W.R.; Adamczak, O.; Breuckmann, R.; Lennartz, H.-W.; Boese, R.,
Die Berechnung von Resonanzenergien; das MM2ERW-Kraftfeld,
Chem. Ber., 1991, 124, 2499-2521. [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]
Notes
Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
Cp,liquid Constant pressure heat capacity of liquid Pc Critical pressure Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature Vc Critical volume ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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