Heptacosane

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 by: Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of solid

Cp,solid (cal/mol*K) Temperature (K) Reference Comment
198.313.Verdonk, 1938crystaline, β phase; Also data for α form, 1117 J/mol*K at 328 K, and liquid, 828 J/mol*K at 338 K.

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
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tfus332. ± 1.KAVGN/AAverage of 19 values; Individual data points
Quantity Value Units Method Reference Comment
Ttriple332.KN/ASchaerer, Busso, et al., 1955Crystal phase 1 phase; Uncertainty assigned by TRC = 0.1 K; TRC
Quantity Value Units Method Reference Comment
Δsub46.8 ± 7.2kcal/molBPiacente, Pompili, et al., 1991AC

Reduced pressure boiling point

Tboil (K) Pressure (atm) Reference Comment
543.20.020Weast and Grasselli, 1989BS

Enthalpy of vaporization

ΔvapH (kcal/mol) Temperature (K) Method Reference Comment
31.5 ± 0.2423.TEPiacente, Fontana, et al., 1994Based on data from 401. to 441. K.; AC
22.5523.ME,TE,GSPiacente, Pompili, et al., 1991Based on data from 508. to 570. K.; AC
27.94 ± 0.72421.TEPompili and Piacente, 1990Based on data from 401. to 441. K.; AC
24.93488.A,ESTStephenson and Malanowski, 1987Based on data from 473. to 695. K. See also Kudchadker and Zwolinski, 1966.; AC

Antoine Equation Parameters

log10(P) = A − (B / (T + C))
    P = vapor pressure (atm)
    T = temperature (K)

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

Temperature (K) A B C Reference Comment
351.3 to 434.86.250523654.268-86.045Morecroft, 1964Coefficents calculated by NIST from author's data.

Enthalpy of fusion

ΔfusH (kcal/mol) Temperature (K) Method Reference Comment
15.0331.6DSCMondieig, Rajabalee, et al., 2004AC
14.11332.1DSCLourdin, Roux, et al., 1992AC

Entropy of fusion

ΔfusS (cal/mol*K) Temperature (K) Reference Comment
1.70318.Lourdin, Roux, et al., 1992, 2CAL
19.30325.4
42.500332.1

Enthalpy of phase transition

ΔHtrs (kcal/mol) Temperature (K) Initial Phase Final Phase Reference Comment
6.9199320.25crystaline, IIcrystaline, ISchaerer, Busso, et al., 1955, 2DH
14.440331.95crystaline, IliquidSchaerer, Busso, et al., 1955, 2DH

Entropy of phase transition

ΔStrs (cal/mol*K) Temperature (K) Initial Phase Final Phase Reference Comment
21.6320.25crystaline, IIcrystaline, ISchaerer, Busso, et al., 1955, 2DH
43.50331.95crystaline, IliquidSchaerer, Busso, et al., 1955, 2DH

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.

Verdonk, 1938
Verdonk, G., Calorimetric analysis of paraffins - Contributions to the general subject of "calorimetric analysis" by J. Straub and R.N.M.A. Malataux, Chem. Weekblad, 1938, 35, 741-743. [all data]

Schaerer, Busso, et al., 1955
Schaerer, A.A.; Busso, C.J.; Smith, A.E.; Skinner, L.B., Properties of Pure Normal Alkanes in the C17 to C36 Range, J. Am. Chem. Soc., 1955, 77, 2017-8. [all data]

Piacente, Pompili, et al., 1991
Piacente, Vincenzo; Pompili, Tiziano; Scardala, Paolo; Ferro, Daniela, Temperature dependence of the vaporization enthalpies of n-alkanes from vapour-pressure measurements, The Journal of Chemical Thermodynamics, 1991, 23, 4, 379-396, https://doi.org/10.1016/S0021-9614(05)80092-8 . [all data]

Weast and Grasselli, 1989
CRC Handbook of Data on Organic Compounds, 2nd Editon, Weast,R.C and Grasselli, J.G., ed(s)., CRC Press, Inc., Boca Raton, FL, 1989, 1. [all data]

Piacente, Fontana, et al., 1994
Piacente, Vincenzo; Fontana, Danilo; Scardala, Paolo, Enthalpies of Vaporization of a Homologous Series of n-Alkanes Determined from Vapor Pressure Measurements, J. Chem. Eng. Data, 1994, 39, 2, 231-237, https://doi.org/10.1021/je00014a009 . [all data]

Pompili and Piacente, 1990
Pompili, T.; Piacente, V., Enthalpy of vaporization of n-heptacosane and n-nonacosane from their vapour pressure determinations, Thermochimica Acta, 1990, 170, 289-291, https://doi.org/10.1016/0040-6031(90)80548-D . [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]

Kudchadker and Zwolinski, 1966
Kudchadker, A.P.; Zwolinski, B.J., Vapor Pressure and Boiling Points of Normal Alkanes, C 21 to C 100 ., J. Chem. Eng. Data, 1966, 11, 2, 253-255, https://doi.org/10.1021/je60029a039 . [all data]

Morecroft, 1964
Morecroft, D.W., Vapor Pressures of Some High Molecular Weight Hydrocarbons., J. Chem. Eng. Data, 1964, 9, 4, 488-490, https://doi.org/10.1021/je60023a003 . [all data]

Mondieig, Rajabalee, et al., 2004
Mondieig, D.; Rajabalee, F.; Metivaud, V.; Oonk, H.A.J.; Cuevas-Diarte, M.A., n -Alkane Binary Molecular Alloys, Chem. Mater., 2004, 16, 5, 786-798, https://doi.org/10.1021/cm031169p . [all data]

Lourdin, Roux, et al., 1992
Lourdin, D.; Roux, A.H.; Grolier, J.-P.E.; Buisine, J.-M., Thermobarometric and differential scanning calorimetric study of the polymorphism of some even and odd paraffins (C26, C27, C40, C60), Thermochimica Acta, 1992, 204, 1, 99-110, https://doi.org/10.1016/0040-6031(92)80319-R . [all data]

Lourdin, Roux, et al., 1992, 2
Lourdin, D.; Roux, A.H.; Grolier, J.-P.E.; Buisine, J.-M., Thermobarometric and differential scanning calorimetric study of the polymorphism of some even and odd paraffins (C26, C27, C40, C60), Thermochim. Acta, 1992, 204, 1, 99, https://doi.org/10.1016/0040-6031(92)80319-R . [all data]

Schaerer, Busso, et al., 1955, 2
Schaerer, A.A.; Busso, C.J.; Smith, A.E.; Skinner, L.B., Properties of pure normal alkanes in the C17 to C36 range, J. Am. Chem. Soc., 1955, 77, 2017-2019. [all data]


Notes

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