Heptane, 4-methyl-

Data at NIST subscription sites:

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.


Condensed 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Δfliquid-251.8 ± 1.2kJ/molCcbProsen and Rossini, 1945ALS
Quantity Value Units Method Reference Comment
Δcliquid-5468.9 ± 1.0kJ/molCcbProsen and Rossini, 1945Corresponding Δfliquid = -251.7 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS

Constant pressure heat capacity of liquid

Cp,liquid (J/mol*K) Temperature (K) Reference Comment
251.08298.15Osborne and Ginnings, 1947T = 278 to 318 K.; DH

Phase change data

Go To: Top, 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

Quantity Value Units Method Reference Comment
Tboil390.9 ± 0.4KAVGN/AAverage of 23 values; Individual data points
Quantity Value Units Method Reference Comment
Tfus151. ± 3.KAVGN/AAverage of 10 values; Individual data points
Quantity Value Units Method Reference Comment
Tc561.7 ± 0.5KN/ADaubert, 1996 
Tc561.7KN/AMajer and Svoboda, 1985 
Tc561.67KN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.4 K; TRC
Quantity Value Units Method Reference Comment
Pc25.4 ± 0.4barN/ADaubert, 1996 
Pc25.419barN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.4053 bar; TRC
Quantity Value Units Method Reference Comment
Vc0.476l/molN/ADaubert, 1996 
Quantity Value Units Method Reference Comment
ρc2.10 ± 0.04mol/lN/ADaubert, 1996 
ρc2.10mol/lN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.04 mol/l; TRC
Quantity Value Units Method Reference Comment
Δvap39. ± 4.kJ/molAVGN/AAverage of 6 values; Individual data points

Enthalpy of vaporization

ΔvapH (kJ/mol) Temperature (K) Method Reference Comment
33.35390.9N/AMajer and Svoboda, 1985 
38.2327.A,MMStephenson and Malanowski, 1987Based on data from 312. to 392. K. See also Willingham, Taylor, et al., 1945.; AC
38.7 ± 0.1313.CMajer, Svoboda, et al., 1979AC
37.4 ± 0.1333.CMajer, Svoboda, et al., 1979AC
36.1 ± 0.1353.CMajer, Svoboda, et al., 1979AC
42.3268.N/AStull, 1947Based on data from 253. to 391. 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)

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Temperature (K) A (kJ/mol) β Tc (K) Reference Comment
298. to 353.57.740.291561.7Majer 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 Comment
252.8 to 390.84.060231347.236-58.539Stull, 1947Coefficents calculated by NIST from author's data.

Enthalpy of fusion

ΔfusH (kJ/mol) Temperature (K) Reference Comment
10.84152.2Acree, 1991AC

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


References

Go To: Top, 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]

Osborne and Ginnings, 1947
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]

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]

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]

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]

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]

Acree, 1991
Acree, William E., Thermodynamic properties of organic compounds: enthalpy of fusion and melting point temperature compilation, Thermochimica Acta, 1991, 189, 1, 37-56, https://doi.org/10.1016/0040-6031(91)87098-H . [all data]


Notes

Go To: Top, Condensed phase thermochemistry data, Phase change data, References