Pentane, 3-methyl-
- Formula: C6H14
- Molecular weight: 86.1754
- IUPAC Standard InChIKey: PFEOZHBOMNWTJB-UHFFFAOYSA-N
- CAS Registry Number: 96-14-0
- 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: 3-Methylpentane; (C2H5)2CHCH3; UN 1208; UN 2462
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Gas phase thermochemistry data
Go To: Top, 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 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 | -171.6 ± 0.96 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°gas | 382.88 ± 0.67 | J/mol*K | N/A | Finke H.L., 1973 | The entropy values S(323.8 K)=397.46 and S(336.5 K)=400.66 J/mol*K were calculated by [ Scott D.W., 1974] from the experimental data [ Finke H.L., 1973].; GT |
Constant pressure heat capacity of gas
Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
98.91 | 200. | Scott D.W., 1974, 2 | Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, Scott D.W., 1974, 2]. This approach gives a better agreement with experimental data than the statistical thermodynamics calculation [ Pitzer K.S., 1946] (see also [ Waddington G., 1949]).; GT |
129.83 | 273.15 | ||
140.1 ± 0.4 | 298.15 | ||
140.88 | 300. | ||
181.17 | 400. | ||
217.48 | 500. | ||
248.95 | 600. | ||
275.73 | 700. | ||
298.74 | 800. | ||
318.82 | 900. | ||
335.98 | 1000. | ||
351.04 | 1100. | ||
364.01 | 1200. | ||
376.56 | 1300. | ||
384.93 | 1400. | ||
397.48 | 1500. |
Constant pressure heat capacity of gas
Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
154.31 | 332.10 | Waddington G., 1949 | GT |
168.41 | 367.55 | ||
181.71 | 402.35 | ||
194.64 | 436.20 | ||
207.32 | 471.15 |
Condensed phase thermochemistry data
Go To: Top, Gas 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 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 | -202.0 ± 0.96 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -4159.9 ± 0.88 | kJ/mol | Ccb | Prosen and Rossini, 1945 | Corresponding ΔfHºliquid = -201.9 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 292.5 | J/mol*K | N/A | Finke and Messerly, 1973 | Thermodynamic properties calculated from a Debye function at 10 K.; DH |
Constant pressure heat capacity of liquid
Cp,liquid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
191.16 | 298.15 | Ohnishi, Fujihara, et al., 1989 | DH |
190.99 | 298.15` | Benson and D'Arcy, 1986 | DH |
190.86 | 298.15 | Benson, D'Arcy, et al., 1984 | DH |
190.77 | 298.15 | Aicart, Kumaran, et al., 1983 | DH |
190.77 | 298.15 | Benson, D'Arcy, et al., 1983 | DH |
187.1 | 288.19 | Oguni, Watanabe, et al., 1982 | T = 80 to 370 K. Unsmoothed experimental datum. Heat capacity measured as a check of the calorimeter's performance.; DH |
186.8 | 298.95 | Czarnota, 1980 | DH |
190.67 | 298.15 | Finke and Messerly, 1973 | T = 10 to 330 K.; DH |
187.36 | 298.1 | Stull, 1937 | T = 90 to 320 K.; DH |
Constant pressure heat capacity of solid
Cp,solid (J/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
190.83 | 298.15 | Douslin and Huffman, 1946 | T = 13 to 300 K.; DH |
Phase change data
Go To: Top, Gas phase thermochemistry data, Condensed 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
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 336.4 ± 0.4 | K | AVG | N/A | Average of 53 out of 57 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 155.15 | K | N/A | Hoog, Smittenberg, et al., 1937 | Uncertainty assigned by TRC = 2. K; TRC |
Tfus | 155.15 | K | N/A | Bruun and Hicks-Brunn, 1930 | Uncertainty assigned by TRC = 1. K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 110.25 | K | N/A | Finke and Messerly, 1973, 2 | Uncertainty assigned by TRC = 0.006 K; by extrapolation of 1/f to 0; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 504. ± 4. | K | AVG | N/A | Average of 8 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 31.1 ± 0.6 | 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 | 2.72 | 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° | 30.3 ± 0.2 | kJ/mol | AVG | N/A | Average of 6 values; Individual data points |
Enthalpy of vaporization
ΔvapH (kJ/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
28.06 | 336.4 | N/A | Majer and Svoboda, 1985 | |
29.9 | 331. | N/A | Loras, Aucejo, et al., 1999 | Based on data from 316. to 361. K.; AC |
30.5 | 308. | A | Stephenson and Malanowski, 1987 | Based on data from 293. to 338. K.; AC |
29.5 ± 0.1 | 313. | C | Majer, Svoboda, et al., 1979 | AC |
28.3 ± 0.1 | 333. | C | Majer, Svoboda, et al., 1979 | AC |
27.0 ± 0.1 | 353. | C | Majer, Svoboda, et al., 1979 | AC |
30.00 ± 0.008 | 303.1 | C | Waddington, Smith, et al., 1949 | ALS |
30.0 ± 0.1 | 303. | C | Waddington, Smith, et al., 1949 | AC |
28.8 ± 0.1 | 324. | C | Waddington, Smith, et al., 1949 | AC |
28.1 ± 0.1 | 336. | C | Waddington, Smith, et al., 1949 | AC |
30.2 | 303. | MM | Willingham, Taylor, et al., 1945 | Based on data from 288. to 337. K.; AC |
Enthalpy of vaporization
ΔvapH = A exp(-αTr)
(1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kJ/mol)
Tr = reduced temperature (T / Tc)
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Temperature (K) | 298. to 353. |
---|---|
A (kJ/mol) | 45.24 |
α | 0. |
β | 0.2703 |
Tc (K) | 504.4 |
Reference | Majer and Svoboda, 1985 |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (bar)
T = temperature (K)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A | B | C | Reference |
---|---|---|---|---|
288.44 to 337.23 | 3.97377 | 1152.368 | -46.021 | Williamham, Taylor, et al., 1945 |
Enthalpy of fusion
ΔfusH (kJ/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
5.31 | 110.3 | Domalski and Hearing, 1996 | AC |
Enthalpy of phase transition
ΔHtrs (kJ/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
5.3032 | 110.26 | crystaline, I | liquid | Finke and Messerly, 1973 | DH |
Entropy of phase transition
ΔStrs (J/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
48.101 | 110.26 | crystaline, I | liquid | Finke and Messerly, 1973 | DH |
References
Go To: Top, Gas phase thermochemistry data, Condensed 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]
Finke H.L., 1973
Finke H.L.,
3-Methylpentane and 3-methylheptane: low-temperature thermodynamic properties,
J. Chem. Thermodyn., 1973, 5, 247-257. [all data]
Scott D.W., 1974
Scott D.W.,
Correlation of the chemical thermodynamic properties of alkane hydrocarbons,
J. Chem. Phys., 1974, 60, 3144-3165. [all data]
Scott D.W., 1974, 2
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]
Pitzer K.S., 1946
Pitzer K.S.,
The entropies and related properties of branched paraffin hydrocarbons,
Chem. Rev., 1946, 39, 435-447. [all data]
Waddington G., 1949
Waddington G.,
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]
Finke and Messerly, 1973
Finke, H.L.; Messerly, J.F.,
3-Methylpentane and 3-methylheptane: low-temperature thermodynamic properties,
J. Chem. Thermodynam., 1973, 5, 247-257. [all data]
Ohnishi, Fujihara, et al., 1989
Ohnishi, K.; Fujihara, I.; Murakami, S.,
Thermodynamic properties of decalins mixed with hexane isomers at 298.15K. 1. Excess enthalpies and excess isobaric heat capacities,
Fluid Phase Equilib., 1989, 46, 59-72. [all data]
Benson and D'Arcy, 1986
Benson, G.C.; D'Arcy, P.J.,
Heat capacities of binary mixtures of n-octane with each of the hexane isomers at 298.15 K,
Can. J. Chem., 1986, 64, 2139-2141. [all data]
Benson, D'Arcy, et al., 1984
Benson, G.C.; D'Arcy, P.J.; Kumaran, M.K.,
Heat capacities of binary mixtures of n-heptane with hexane isomers,
Thermochim. Acta, 1984, 75, 353-360. [all data]
Aicart, Kumaran, et al., 1983
Aicart, E.; Kumaran, M.K.; Halpin, C.J.; Benson, G.C.,
Ultrasonic speeds and isentropic compressibilities of 2-methylpentan-1-ol with hexane isomers at 298.15 K,
J. Chem. Thermodynam., 1983, 15, 1189-1197. [all data]
Benson, D'Arcy, et al., 1983
Benson, G.C.; D'Arcy, P.J.; Sugamori, M.E.,
Heat capacities of binary mixtures of 1-hexanol with hexane isomers at 298.15 K,
Thermochim. Acta, 1983, 71, 161-166. [all data]
Oguni, Watanabe, et al., 1982
Oguni, M.; Watanabe, K.; Matsuo, T.; Suga, H.; Seki, S.,
Construction of an adiabatic calorimeter workable under constant high pressure,
Bull. Chem. Soc. Japan, 1982, 55, 77-84. [all data]
Czarnota, 1980
Czarnota, I.,
Heat capacity of 3-methylpentane at high pressures, Bull. Acad. Pol. Sci.,
Ser. Sci. Chim., 1980, 28(9-10), 651-659. [all data]
Stull, 1937
Stull, D.R.,
A semi-micro calorimeter for measuring heat capacities at low temperatures,
J. Am. Chem. Soc., 1937, 59, 2726-2733. [all data]
Douslin and Huffman, 1946
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]
Hoog, Smittenberg, et al., 1937
Hoog, H.; Smittenberg, J.; Visser, G.H.,
Composition of the Primary Polymerization Prod. of Propene and Butenes
in IIe Congr. Mondial Pet. 2, Sect. 2, Phys. Chim. Raffin- age, p 489, 1937. [all data]
Bruun and Hicks-Brunn, 1930
Bruun, J.H.; Hicks-Brunn, M.M.,
The Isolation of the Isomers of Hexane from Petroleum,
J. Res. Natl. Bur. Stand. (U. S.), 1930, 5, 933. [all data]
Finke and Messerly, 1973, 2
Finke, H.L.; Messerly, J.F.,
3-Methylpentane and 3-Methylheptane: Low-temperature Thermo. Properties properties,
J. Chem. Thermodyn., 1973, 5, 247. [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]
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]
Loras, Aucejo, et al., 1999
Loras, Sonia; Aucejo, Antonio; Muñoz, Rosa,
Vapor--liquid equilibria in the systems 3-methylpentane+methyl 1,1-dimethylethyl ether and 3-methylpentane+methyl 1,1-dimethylpropyl ether at 101.3 kPa,
Fluid Phase Equilibria, 1999, 156, 1-2, 185-195, https://doi.org/10.1016/S0378-3812(99)00028-X
. [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]
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]
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,
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. [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,
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. [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,
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. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Cp,liquid Constant pressure heat capacity of liquid Cp,solid Constant pressure heat capacity of solid 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 ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition 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 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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