Hexane, 3,4-dimethyl-
- Formula: C8H18
- Molecular weight: 114.2285
- IUPAC Standard InChIKey: RNTWWGNZUXGTAX-UHFFFAOYSA-N
- CAS Registry Number: 583-48-2
- 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. - Stereoisomers:
- Other names: 3,4-Dimethylhexane; C2H5CH(CH3)CH(CH3)C2H5
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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 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 | -213.0 ± 1.5 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Constant pressure heat capacity of gas
Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
116.78 | 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 |
166.90 | 273.15 | ||
182.3 ± 1.4 | 298.15 | ||
183.47 | 300. | ||
240.25 | 400. | ||
288.78 | 500. | ||
329.70 | 600. | ||
364.43 | 700. | ||
393.71 | 800. | ||
419.24 | 900. | ||
441.00 | 1000. | ||
460.24 | 1100. | ||
476.98 | 1200. | ||
493.71 | 1300. | ||
506.26 | 1400. | ||
518.82 | 1500. |
Constant pressure heat capacity of gas
Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
245.18 | 406.7 | Barrow G.M., 1951 | GT |
272.38 | 462.3 | ||
300.41 | 522.6 |
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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 391. ± 1. | K | AVG | N/A | Average of 21 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 568.8 ± 0.5 | K | N/A | Daubert, 1996 | |
Tc | 568.8 | K | N/A | Majer and Svoboda, 1985 | |
Tc | 568.78 | K | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 26.9 ± 0.4 | bar | N/A | Daubert, 1996 | |
Pc | 26.921 | bar | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4053 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.466 | l/mol | N/A | Daubert, 1996 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.14 ± 0.04 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.14 | mol/l | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.04 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 39.03 | kJ/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 39.0 ± 0.1 | kJ/mol | C | Osborne and Ginnings, 1947 | AC |
ΔvapH° | 38.97 | kJ/mol | C | Osborne and Ginnings, 1947, 2 | ALS |
ΔvapH° | 33.0 | kJ/mol | V | Fajans, 1920 | ALS |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
33.24 | 390.9 | N/A | Majer and Svoboda, 1985 | |
37.7 | 328. | A,MM | Stephenson and Malanowski, 1987 | Based on data from 313. to 392. K. See also Willingham, Taylor, et al., 1945.; AC |
41.3 | 266. | N/A | Stull, 1947 | Based on data from 251. to 390. K.; AC |
Enthalpy of vaporization
ΔvapH =
A exp(-βTr) (1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kJ/mol)
Tr = reduced temperature (T / Tc)
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Temperature (K) | A (kJ/mol) | β | Tc (K) | Reference | Comment |
---|---|---|---|---|---|
298. to 391. | 55.07 | 0.2729 | 568.8 | Majer and Svoboda, 1985 |
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 |
---|---|---|---|---|---|
251.1 to 390.8 | 4.09815 | 1382.877 | -52.831 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
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.
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]
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]
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]
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]
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]
Osborne and Ginnings, 1947
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]
Osborne and Ginnings, 1947, 2
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]
Fajans, 1920
Fajans, K.,
Die Energie der Atombindungen im Diamanten und in aliphatischen Kohlenwasserstoffen,
Ber., 1920, 53, 643-665. [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]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Pc Critical pressure Tboil Boiling point Tc Critical temperature Vc Critical volume ΔfH°gas Enthalpy of formation of gas 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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