Heptane, 3-methyl-
- Formula: C8H18
- Molecular weight: 114.2285
- IUPAC Standard InChIKey: LAIUFBWHERIJIH-UHFFFAOYSA-N
- CAS Registry Number: 589-81-1
- 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. - Isotopologues:
- Stereoisomers:
- Other names: 3-Methylheptane; 2-Ethylhexane
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Phase change data
Go To: Top, 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
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 | 392. ± 1. | K | AVG | N/A | Average of 27 out of 28 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 152. ± 1. | K | AVG | N/A | Average of 15 out of 16 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 152.65 | K | N/A | Finke and Messerly, 1973 | Uncertainty assigned by TRC = 0.008 K; by exatroplation to 1/f = 0; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 563.6 ± 0.5 | K | N/A | Daubert, 1996 | |
Tc | 563.7 | K | N/A | Majer and Svoboda, 1985 | |
Tc | 563.60 | K | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 25.2 ± 0.4 | atm | N/A | Daubert, 1996 | |
Pc | 25.127 | atm | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4000 atm; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.464 | l/mol | N/A | Daubert, 1996 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.15 ± 0.04 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.15 | mol/l | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.04 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 9.532 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 9.51 ± 0.05 | kcal/mol | C | An, Hu, et al., 1987 | AC |
ΔvapH° | 9.51 | kcal/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 9.51 ± 0.02 | kcal/mol | C | Osborne and Ginnings, 1947 | AC |
ΔvapH° | 9.520 | kcal/mol | C | Osborne and Ginnings, 1947, 2 | ALS |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
8.045 | 392.1 | N/A | Majer and Svoboda, 1985 | |
9.58 | 301. | A | Stephenson and Malanowski, 1987 | Based on data from 286. to 393. K.; AC |
9.94 | 271. | IP | Stephenson and Malanowski, 1987 | Based on data from 238. to 286. K. See also Osborn and Douslin, 1974.; AC |
9.15 | 331. | MM | Willingham, Taylor, et al., 1945 | Based on data from 316. to 393. K.; AC |
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 |
---|---|---|---|---|---|
238. to 288. | 4.50677 | 1568.919 | -40.686 | Osborn and Douslin, 1974 | Coefficents calculated by NIST from author's data. |
315.82 to 392.96 | 4.01864 | 1331.53 | -60.555 | Williamham, Taylor, et al., 1945 |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
2.789 | 152.6 | Domalski and Hearing, 1996 | AC |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
2.7949 | 152.6574 | crystaline, I | liquid | Finke and Messerly, 1973, 2 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
1.832 | 152.6574 | crystaline, I | liquid | Finke and Messerly, 1973, 2 | DH |
References
Go To: Top, Phase change data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Finke and Messerly, 1973
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]
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]
An, Hu, et al., 1987
An, Xuwu; Hu, Riheng; Wang, Hu; Wu, Mali; Zou, Yongkuang,
Enthalpies of Vaporization of α- and β-Pinene,
Acta Phys. Chim. Sin., 1987, 3, 6, 668-671, https://doi.org/10.3866/PKU.WHXB19870621
. [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
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]
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]
Osborn and Douslin, 1974
Osborn, Ann G.; Douslin, Donald R.,
Vapor-pressure relations for 15 hydrocarbons,
J. Chem. Eng. Data, 1974, 19, 2, 114-117, https://doi.org/10.1021/je60061a022
. [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]
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]
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]
Finke and Messerly, 1973, 2
Finke, H.L.; Messerly, J.F.,
3-Methylpentane and 3-methylheptane: low-temperature thermodynamic properties,
J. Chem. Thermodynam., 1973, 5, 247-257. [all data]
Notes
Go To: Top, Phase change data, References
- Symbols used in this document:
Pc Critical pressure 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 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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