Pentane, 2-methyl-
- Formula: C6H14
- Molecular weight: 86.1754
- IUPAC Standard InChIKey: AFABGHUZZDYHJO-UHFFFAOYSA-N
- CAS Registry Number: 107-83-5
- 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: Isohexane; 2-Methylpentane; (CH3)2CH(CH2)2CH3; Methyl pentane; UN 1208; UN 2462; Esano isomeri
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Phase change data
Go To: Top, 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:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
BS - Robert L. Brown and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
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 |
---|---|---|---|---|---|
Tboil | 334. ± 1. | K | AVG | N/A | Average of 71 out of 73 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 120. ± 7. | K | AVG | N/A | Average of 21 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 119.55 | K | N/A | Douslin and Huffman, 1946 | Uncertainty assigned by TRC = 0.07 K; TRC |
Ttriple | 119.55 | K | N/A | Huffman, 1945 | Uncertainty assigned by TRC = 0.03 K; based on To = 273.16 K; TRC |
Ttriple | 119.7 | K | N/A | Stull, 1937 | Uncertainty assigned by TRC = 0.1 K; measured by Wojciechowski; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 497.8 ± 0.4 | K | AVG | N/A | Average of 10 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 30.35 ± 0.07 | bar | AVG | N/A | Average of 6 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.368 | l/mol | N/A | Daubert, 1996 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.72 ± 0.02 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.734 | mol/l | N/A | Holcomb, Magee, et al., 1995 | Uncertainty assigned by TRC = 0.05 mol/l; TRC |
ρc | 2.72 | mol/l | N/A | Genco, Teja, et al., 1980 | Uncertainty assigned by TRC = 0.06 mol/l; TRC |
ρc | 2.73 | mol/l | N/A | Kay, 1946 | Uncertainty assigned by TRC = 0.02 mol/l; by extrapolation of rectilinear diameter to Tc; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 29. ± 4. | kJ/mol | AVG | N/A | Average of 6 values; Individual data points |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
27.79 | 333.4 | N/A | Majer and Svoboda, 1985 | |
30.2 | 305. | N/A | Sapei, Uusi-Kyyny, et al., 2010 | Based on data from 290. to 333. K.; AC |
30.0 | 316. | N/A | Pokki, Uusi-Kyyny, et al., 2002 | Based on data from 301. to 333. K.; AC |
29.7 | 325. | N/A | Aucejo, Loras, et al., 1998 | Based on data from 310. to 359. K.; AC |
30.5 | 308. | A | Stephenson and Malanowski, 1987 | Based on data from 293. to 335. K.; AC |
28.7 ± 0.1 | 318. | C | Waddington, Smith, et al., 1949 | AC |
27.8 ± 0.1 | 333. | C | Waddington, Smith, et al., 1949 | AC |
30.4 | 301. | MM | Willingham, Taylor, et al., 1945 | Based on data from 286. to 334. K.; AC |
29.8 ± 0.2 | 293. | C | Lemons and Felsing, 1943 | AC |
29.0 ± 0.2 | 313. | C | Lemons and Felsing, 1943 | AC |
27.6 ± 0.2 | 333. | C | Lemons and Felsing, 1943 | AC |
26.9 ± 0.2 | 353. | C | Lemons and Felsing, 1943 | 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 333. | 45.25 | 0.2739 | 497.5 | 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 |
---|---|---|---|---|
285.91 to 334.22 | 3.9640 | 1135.41 | -46.578 | Williamham, Taylor, et al., 1945 |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
6.268 | 119.55 | Douslin and Huffman, 1946, 2 | DH |
6.27 | 119.6 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
52.43 | 119.55 | Douslin and Huffman, 1946, 2 | DH |
Reaction thermochemistry data
Go To: Top, Phase change 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 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: H2 + C6H12 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -116.3 ± 0.43 | kJ/mol | Chyd | Rogers, Crooks, et al., 1987 | liquid phase |
ΔrH° | -115.6 ± 2.2 | kJ/mol | Chyd | Molnar, Rachford, et al., 1984 | liquid phase; solvent: Dioxane |
By formula: H2 + C6H12 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -116.9 ± 0.38 | kJ/mol | Chyd | Rogers, Crooks, et al., 1987 | liquid phase |
ΔrH° | -114. | kJ/mol | Chyd | Turner, Nettleton, et al., 1958 | liquid phase; solvent: Acetic acid |
By formula: H2 + C6H12 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -114.2 ± 0.57 | kJ/mol | Chyd | Rogers, Crooks, et al., 1987 | liquid phase |
ΔrH° | -110. | kJ/mol | Chyd | Turner, Nettleton, et al., 1958 | liquid phase; solvent: Acetic acid |
By formula: 2H2 + C6H10 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -270. ± 0.4 | kJ/mol | Chyd | Roth, Kirmse, et al., 1982 | liquid phase; solvent: Isooctane |
By formula: C6H14 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -5.44 ± 0.88 | kJ/mol | Ciso | Prosen and Rossini, 1941 | liquid phase; Calculated from ΔHc |
By formula: H2 + C6H12 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -126.7 ± 0.43 | kJ/mol | Chyd | Rogers, Crooks, et al., 1987 | liquid phase |
By formula: H2 + C6H12 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | -111.6 ± 0.74 | kJ/mol | Chyd | Rogers, Crooks, et al., 1987 | liquid phase |
By formula: C6H14 = C6H14
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 0.92 ± 0.46 | kJ/mol | Eqk | Roganov, Kabo, et al., 1972 | gas phase; At 368 K |
Gas phase ion energetics data
Go To: Top, 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:
LL - Sharon G. Lias and Joel F. Liebman
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.04 | EST | Luo and Pacey, 1992 | LL |
9.89 ± 0.15 | EQ | Mautner(Meot-Ner), Sieck, et al., 1981 | LLK |
10.12 | PI | Watanabe, Nakayama, et al., 1962 | RDSH |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
C3H6+ | 10.91 ± 0.05 | C3H8 | PI | Steiner, Giese, et al., 1961 | RDSH |
C3H7+ | ~11.35 ± 0.10 | C3H7 | PI | Steiner, Giese, et al., 1961 | RDSH |
C4H8+ | 10.65 ± 0.015 | C2H6 | PI | Steiner, Giese, et al., 1961 | RDSH |
C4H9+ | 10.73 ± 0.02 | C2H5 | PI | Steiner, Giese, et al., 1961 | RDSH |
C5H10+ | 10.835 ± 0.025 | CH4 | PI | Steiner, Giese, et al., 1961 | RDSH |
C5H11+ | 10.865 ± 0.085 | CH3 | PI | Steiner, Giese, et al., 1961 | RDSH |
References
Go To: Top, 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.
Douslin and Huffman, 1946
Douslin, D.R.; Huffman, H.M.,
Low-Temperature Thermal Data on the Five Isomeric Hexanes,
J. Am. Chem. Soc., 1946, 68, 1704. [all data]
Huffman, 1945
Huffman, H.M.,
Personal Commun., U. S. Bur. Mines, Bartlesville, OK, July 25, 1945. [all data]
Stull, 1937
Stull, D.R.,
A Semi-micro Calorimeter for Measuring Heat Capacities at Low Temp.,
J. Am. Chem. Soc., 1937, 59, 2726. [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]
Holcomb, Magee, et al., 1995
Holcomb, C.D.; Magee, J.W.; Haynes, W.M.,
Density Measurements on Natural Gas Liquids, Research Report RR-147, Gas Processors Association Project 916, 1995. [all data]
Genco, Teja, et al., 1980
Genco, J.M.; Teja, A.S.; Kay, W.B.,
Study of the critical and azeotropic behavior of binary mixtures I critical states of perfluoromethylcyclohexane + isomeric hexane systems,
J. Chem. Eng. Data, 1980, 25, 350. [all data]
Kay, 1946
Kay, W.B.,
The Vapor Pressures and Saturated Liquid and Vapor Densities of the Isomeric Hexanes,
J. Am. Chem. Soc., 1946, 68, 1336. [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]
Sapei, Uusi-Kyyny, et al., 2010
Sapei, Erlin; Uusi-Kyyny, Petri; Keskinen, Kari I.; Alopaeus, Ville,
Phase equilibria of binary systems of 3-methylthiophene with four different hydrocarbons,
Fluid Phase Equilibria, 2010, 288, 1-2, 155-160, https://doi.org/10.1016/j.fluid.2009.11.004
. [all data]
Pokki, Uusi-Kyyny, et al., 2002
Pokki, Juha-Pekka; Uusi-Kyyny, Petri; Aittamaa, Juhani; Liukkonen, Simo,
Vapor-Liquid Equilibrium for the 2-Methylpentane + 2-Methyl-2-propanol and + 2-Butanol Systems at 329 K,
J. Chem. Eng. Data, 2002, 47, 2, 371-375, https://doi.org/10.1021/je0155296
. [all data]
Aucejo, Loras, et al., 1998
Aucejo, Antonio; Loras, Sonia; Muñoz, Rosa; Reich, Ricardo; Segura, Hugo,
Isobaric Vapor-Liquid Equilibrium in the Systems 2-Methylpentane + Methyl 1,1-Dimethylethyl Ether, + Ethyl 1,1-Dimethylethyl Ether, and + Methyl 1,1-Dimethylpropyl Ether,
J. Chem. Eng. Data, 1998, 43, 6, 973-977, https://doi.org/10.1021/je980090b
. [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]
Waddington, Smith, et al., 1949
Waddington, G.; Smith, J.C.; Scott, D.W.; Huffman, H.M.,
Experimental vapor heat capacities and heats of vaporization of 2-methylpentane, 3-methylpentane and 2,3-dimethylbutane,
J. Am. Chem. Soc., 1949, 71, 3902-3906. [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]
Lemons and Felsing, 1943
Lemons, Joe Fred; Felsing, W.A.,
The Heats of Vaporization of Some Hexanes 1,
J. Am. Chem. Soc., 1943, 65, 1, 46-48, https://doi.org/10.1021/ja01241a015
. [all data]
Williamham, Taylor, et al., 1945
Williamham, 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. Stand. (U.S.), 1945, 35, 3, 219-244, https://doi.org/10.6028/jres.035.009
. [all data]
Douslin and Huffman, 1946, 2
Douslin, D.R.; Huffman, H.M.,
Low-temperature thermal data on the five isometric hexanes,
J. Am. Chem. Soc., 1946, 68, 1704-1708. [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, Crooks, et al., 1987
Rogers, D.W.; Crooks, E.; Dejroongruang, K.,
Enthalpies of hydrogenation of the hexenes,
J. Chem. Thermodyn., 1987, 19, 1209-1215. [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]
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]
Roth, Kirmse, et al., 1982
Roth, W.R.; Kirmse, W.; Hoffmann, W.; Lennartz, H.W.,
Heats of hydrogenation. III. Effect of fluoro substituents on the thermal rearrangement of cyclopropane systems,
Chem. Ber., 1982, 115, 2508-2515. [all data]
Prosen and Rossini, 1941
Prosen, E.J.R.; Rossini, F.D.,
Heats of isomerization of the five hexanes,
J. Res. NBS, 1941, 27, 289-310. [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]
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]
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]
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]
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]
Notes
Go To: Top, Phase change data, Reaction thermochemistry data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy Pc Critical pressure Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature Vc Critical volume 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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