Hexane, 2-methyl-
- Formula: C7H16
- Molecular weight: 100.2019
- IUPAC Standard InChIKey: GXDHCNNESPLIKD-UHFFFAOYSA-N
- CAS Registry Number: 591-76-4
- 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: 2-Methylhexane; Isoheptane
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Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -46.60 ± 0.30 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
ΔfH°gas | -46.89 | kcal/mol | N/A | Davies and Gilbert, 1941 | Value computed using ΔfHliquid° value of -231.0±1.0 kj/mol from Davies and Gilbert, 1941 and ΔvapH° value of 34.8 kj/mol from Prosen and Rossini, 1945.; DRB |
Quantity | Value | Units | Method | Reference | Comment |
S°gas | 100.38 | cal/mol*K | N/A | Huffman H.M., 1961 | GT |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
28.339 | 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 |
36.511 | 273.15 | ||
39.32 ± 0.05 | 298.15 | ||
39.520 | 300. | ||
50.660 | 400. | ||
60.660 | 500. | ||
69.199 | 600. | ||
76.401 | 700. | ||
82.600 | 800. | ||
87.899 | 900. | ||
92.400 | 1000. | ||
96.401 | 1100. | ||
99.799 | 1200. | ||
103.00 | 1300. | ||
106.00 | 1400. | ||
108.00 | 1500. |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction 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:
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 | -54.93 ± 0.30 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
ΔfH°liquid | -55.2 ± 0.3 | kcal/mol | Ccb | Davies and Gilbert, 1941 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -1149.97 ± 0.28 | kcal/mol | Ccb | Prosen and Rossini, 1945 | Corresponding ΔfHºliquid = -54.91 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -1149.5 ± 0.3 | kcal/mol | Ccb | Davies and Gilbert, 1941 | Corresponding ΔfHºliquid = -55.37 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 77.280 | cal/mol*K | N/A | Huffman, Gross, et al., 1961 | DH |
S°liquid | 75.31 | cal/mol*K | N/A | Huffman, Parks, et al., 1930 | Extrapolation below 90 K, 70.12 J/mol*K. Based on previously published specific heat data, 30PAR/HUF.; DH |
S°liquid | 75.19 | cal/mol*K | N/A | Parks, Huffman, et al., 1930 | Extrapolation below 90 K.; DH |
Constant pressure heat capacity of liquid
Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
53.279 | 298.15 | Huffman, Gross, et al., 1961 | T = 10 to 300 K.; DH |
52.39 | 292.4 | Parks, Huffman, et al., 1930 | T = 86 to 293 K. Value is unsmoothed experimental datum.; DH |
Phase change 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:
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
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 363.2 ± 0.5 | K | AVG | N/A | Average of 44 out of 48 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 154.7 ± 0.6 | K | AVG | N/A | Average of 22 out of 23 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 154.6 ± 0.8 | K | AVG | N/A | Average of 6 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 530.5 ± 0.5 | K | AVG | N/A | Average of 6 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 27.0 ± 0.2 | atm | N/A | Daubert, 1996 | |
Pc | 27.14 | atm | N/A | Abara, Jennings, et al., 1988 | Uncertainty assigned by TRC = 0.25 atm; TRC |
Pc | 26.971 | atm | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4000 atm; TRC |
Pc | 27.2000 | atm | N/A | Edgar and Calingaert, 1929 | Uncertainty assigned by TRC = 0.5000 atm; measured by Keys and Kleinschmidt; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.421 | l/mol | N/A | Daubert, 1996 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.38 ± 0.02 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.38 | mol/l | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.05 mol/l; ~; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 8.360 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 8.34 ± 0.02 | kcal/mol | C | Majer, Svoboda, et al., 1979 | AC |
ΔvapH° | 8.32 | kcal/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 8.32 | kcal/mol | N/A | Huffman, Gross, et al., 1961 | Based on data from 273. to 318. K.; AC |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
7.318 | 363.2 | N/A | Majer and Svoboda, 1985 | |
8.27 | 311. | A | Stephenson and Malanowski, 1987 | Based on data from 296. to 365. K.; AC |
8.10 ± 0.02 | 313. | C | Majer, Svoboda, et al., 1979 | AC |
7.82 ± 0.02 | 333. | C | Majer, Svoboda, et al., 1979 | AC |
7.48 ± 0.02 | 353. | C | Majer, Svoboda, et al., 1979 | AC |
8.32 | 306. | N/A | Forziati, Norris, et al., 1949 | Based on data from 291. to 364. K.; AC |
Enthalpy of vaporization
ΔvapH =
A exp(-βTr) (1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kcal/mol)
Tr = reduced temperature (T / Tc)
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Temperature (K) | A (kcal/mol) | β | Tc (K) | Reference | Comment |
---|---|---|---|---|---|
298. to 353. | 12. | 0.2879 | 530.3 | Majer and Svoboda, 1985 |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
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Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
291.68 to 364.09 | 4.00082 | 1240.869 | -53.047 | Forziati, Norris, et al., 1949, 2 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
2.195 | 154.90 | Huffman, Gross, et al., 1961 | DH |
2.19 | 154.9 | Domalski and Hearing, 1996 | AC |
2.120 | 154.0 | Huffman, Parks, et al., 1930 | DH |
2.120 | 154.0 | Parks, Huffman, et al., 1930 | DH |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
14.17 | 154.90 | Huffman, Gross, et al., 1961 | DH |
13.77 | 154.0 | Huffman, Parks, et al., 1930 | DH |
13.77 | 154.0 | Parks, Huffman, et al., 1930 | DH |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, 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 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: C7H14 + H2 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -27.80 ± 0.07 | kcal/mol | Chyd | Rogers and Dejroongruang, 1988 | liquid phase; solvent: Hydrocarbone |
By formula: H2 + C7H14 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -28.27 ± 0.07 | kcal/mol | Chyd | Rogers and Dejroongruang, 1988 | liquid phase; solvent: Hydrocarbone |
By formula: H2 + C7H14 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -27.68 ± 0.1 | kcal/mol | Chyd | Rogers and Dejroongruang, 1988 | liquid phase; solvent: Hydrocarbone |
By formula: H2 + C7H14 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -29.78 ± 0.1 | kcal/mol | Chyd | Rogers and Dejroongruang, 1988 | liquid phase; solvent: Hydrocarbone |
By formula: H2 + C7H14 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -26.0 ± 0.2 | kcal/mol | Chyd | Rogers and Dejroongruang, 1988 | liquid phase; solvent: Hydrocarbone |
By formula: H2 + C7H14 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -26.86 ± 0.07 | kcal/mol | Chyd | Rogers and Dejroongruang, 1988 | liquid phase; solvent: Hydrocarbone |
By formula: H2 + C7H14 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -27.56 ± 0.07 | kcal/mol | Chyd | Rogers and Dejroongruang, 1988 | liquid phase; solvent: Hydrocarbone |
By formula: C7H16 = C7H16
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -0.024 ± 0.050 | kcal/mol | Eqk | Roganov, Kabo, et al., 1972 | gas phase; At 368 K |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry 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]
Davies and Gilbert, 1941
Davies, G.F.; Gilbert, E.C.,
Heats of combustion and formation of the nine isomeric heptanes in the liquid state,
J. Am. Chem. Soc., 1941, 63, 2730-2732. [all data]
Huffman H.M., 1961
Huffman H.M.,
Low temperature thermodynamic properties of six isomeric heptanes,
J. Phys. Chem., 1961, 65, 495-503. [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]
Huffman, Gross, et al., 1961
Huffman, H.M.; Gross, M.E.; Scott, D.W.; McCullough, I.P.,
Low temperature thermodynamic properties of six isomeric heptanes,
J. Phys. Chem., 1961, 65, 495-503. [all data]
Huffman, Parks, et al., 1930
Huffman, H.M.; Parks, G.S.; Thomas, S.B.,
Thermal data on organic compounds. VIII. The heat capacities, entropies and free energies of the isomeric heptanes,
J. Am. Chem. Soc., 1930, 52, 3241-3251. [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]
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]
Abara, Jennings, et al., 1988
Abara, J.A.; Jennings, D.W.; Kay, W.B.; Teja, A.S.,
Phase Behavior in the Critical Region of Six Binary Mixtures of 2-Methylalkanes,
J. Chem. Eng. Data, 1988, 33, 242. [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]
Edgar and Calingaert, 1929
Edgar, G.; Calingaert, G.,
Preparation and Properties of the Isomeric Heptanes II. Physical Prop. properties,
J. Am. Chem. Soc., 1929, 51, 1540. [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]
Majer, Svoboda, et al., 1979
Majer, Vladimír; Svoboda, Václav; Hála, Slavoj; Pick, Jirí,
Temperature dependence of heats of vaporization of saturated hydrocarbons C5-C8; Experimental data and an estimation method,
Collect. Czech. Chem. Commun., 1979, 44, 3, 637-651, https://doi.org/10.1135/cccc19790637
. [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]
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]
Forziati, Norris, et al., 1949
Forziati, Alphonse F.; Norris, William R.; Rossini, Frederick D.,
Vapor pressures and boiling points of sixty API-NBS hydrocarbons,
J. RES. NATL. BUR. STAN., 1949, 43, 6, 555-17, https://doi.org/10.6028/jres.043.050
. [all data]
Forziati, Norris, et al., 1949, 2
Forziati, A.F.; Norris, W.R.; Rossini, F.D.,
Vapor Pressures and Boiling Points of Sixty API-NBS Hydrocarbons,
J. Res. Natl. Bur. Stand. (U.S.), 1949, 43, 6, 555-563, https://doi.org/10.6028/jres.043.050
. [all data]
Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D.,
Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III,
J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985
. [all data]
Rogers and Dejroongruang, 1988
Rogers, D.W.; Dejroongruang, K.,
Enthalpies of hydrogenation of the n-heptenes and the methylhexenes,
J. Chem. Thermodyn., 1988, 20, 675-680. [all data]
Roganov, Kabo, et al., 1972
Roganov, G.N.; Kabo, G.Ya.; Andreevskii, D.N.,
Thermodynamics of the isomerization of methylpentanes and methylheptanes,
Neftekhimiya, 1972, 12, 495-500. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Cp,liquid Constant pressure heat capacity of liquid Pc Critical pressure S°gas Entropy of gas at standard conditions S°liquid Entropy of liquid at standard conditions 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°gas Enthalpy of formation of gas at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion 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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