Determination of Purity and Phase Behavior by Adiabatic Calorimetry

  • Edgar F. WestrumJr.


Heating and cooling curves through the melting region of a substance allow calculation of the amount of impurity that is soluble in the liquid phase but insoluble in the crystalline phase as described by several investigators [e.g., 1, 2, 3] and highly developed by others [e.g., 4]. A more precise method of determining purity is the calorimetric procedure. In this technique, the temperature at which the crystalline and liquid phases are in equilibrium is determined as a function of the fraction of the sample liquefied. The depression of the freezing point and the enthalpy of fusion, and hence the cryoscopic constant, are determined in a single experiment. Precise results can be obtained because the sample can be held under adiabatic conditions as long as required for equilibration. The two procedures have been compared experimentally by Glasgow et al. [5]. The calculation of the purity of the sample from its equilibrium melting curve, which has been discussed by various investigators [6, 7, 8, 9, 10, 11, 12], involves straightforward application of ideal solution laws.


Heat Capacity Phase Behavior Mole Percent Ammonium Fluoride Adiabatic Calorimetry 
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  1. 1.
    Washburn, E. W., Ind. Eng. Chem., Ind. Ed., 22, 985 (1930).CrossRefGoogle Scholar
  2. 2.
    White, W. P., J. Phys. Chem., 24, 393 (1920).CrossRefGoogle Scholar
  3. 3.
    Glasgow, A. R., A. J. Streiff, and F. D. Rossini, J. Research Natl. Bur. Standards, 35, 355 (1945).Google Scholar
  4. 4.
    Mair, B. J., A. R. Glasgow, Jr., and F. D. Rossini, J. Research Natl. Bur. Standards, 26, 591 (1941).Google Scholar
  5. 5.
    Glasgow, A. R., Jr., G. S. Ross, A. T. Horton, D. Enagonio, H. D. Dixon, C. P. Saylor, G. T. Furukawa, M. L. Reilly, and J. M. Henning, Anal. Chim. Acta, 17, 54 (1957).CrossRefGoogle Scholar
  6. 6.
    Aston, J. G., M. R. Clines, and H. L. Finke, J. Am. Chem. Soc., 69, 1532 (1947).CrossRefGoogle Scholar
  7. 7.
    Badley, J. H., J. Phys. Chem., 63, 1991 (1959).CrossRefGoogle Scholar
  8. 8.
    Pitzer, K. S., and D. W. Scott, J. Am. Chem. Soc., 63, 2419 (1941).CrossRefGoogle Scholar
  9. 9.
    Rossini, F. D., Chemical Thermodynamics, Wiley, New York, 1950, p. 455.Google Scholar
  10. 10.
    Scott, R. B., C. H. Meyers, R. D. Rands, Jr., F. G. Brickwedde, and N. Bekkedahl, J. Research Natl. Bur. Standards, 35, 39 (1945).Google Scholar
  11. 11.
    Todd, S. S., G. D. Oliver, and H. M. Huffman, J. Am. Chem. Soc., 69, 1519 (1947).CrossRefGoogle Scholar
  12. 12.
    Weissberger, A., ed., Physical Methods of Organic Chemistry 1st ed., Vol. I, Interscience, New York, 1945, p. 350.Google Scholar
  13. 13.
    McCullough, J. P., and G. Waddington, Anal. Chim. Acta, 17, 80 (1957).CrossRefGoogle Scholar
  14. 14.
    Mastrangelo, S. V. R., and R. W. Dornte, J. Am. Chem. Soc, 77, 6200 (1955).CrossRefGoogle Scholar
  15. 15.
    Saylor, C. P., Report of the Subcommission on Physico-Chemical Data, International Union of Pure and Applied Chemistry, at International Calorimetry Conference, Ottawa, Canada, August 18, 1961.Google Scholar
  16. 16.
    U. S. Bureau of Mines, Bartlesville, Okla., unpublished.Google Scholar
  17. 17.
    Aston, J. G., H. L. Finke, J. W. Tooke and M. R. Cines, Anal. Chem., 19, 218 (1947).CrossRefGoogle Scholar
  18. 18.
    Pilcher, G., Anal. Chim. Acta, 17, 144 (1957).CrossRefGoogle Scholar
  19. 19.
    Tunnicliff, D. D., and H. Stone, Anal. Chem., 27, 73 (1955).CrossRefGoogle Scholar
  20. 20.
    Clarke, J. T., H. L. Johnston, and W. DeSorbo, Anal. Chem. 25, 1156 (1953).CrossRefGoogle Scholar
  21. 21.
    Brooks, J. H., and G. Pilcher, J. Chem. Soc., 1959, 1535.Google Scholar
  22. 22.
    Euler, R.D., and E.F. Westrum, Jr., J. Phys.Chem., 65, 1291 (1961).CrossRefGoogle Scholar
  23. 23.
    Lonsdale, K., Nature, 158, 582 (1946).CrossRefGoogle Scholar
  24. 24.
    Pauling, L., “The Nature of the Chemical Bond”, 3rd Ed., Cornell University Press, Ithaca, N.Y., 1960.Google Scholar
  25. 25.
    Zaromb, S., and R. Brill, J. Chem. Phys., 24, 895 (1956).CrossRefGoogle Scholar
  26. 26.
    Brill, R., and S. Zaromb, Nature, 173, 316 (1954).CrossRefGoogle Scholar
  27. 27.
    Yatlow, V. S., and E. M. Polyakova, Zhur. Obschei Khim., 15, 742 (1945).Google Scholar
  28. 28.
    Labowitz, L.C, and E. F. Westrum, Jr., J. Phys. Chem., 65, 408 (1961).CrossRefGoogle Scholar
  29. 29.
    Eucken, A., “Lehrbuch der chemischen Physik”, Akad. Verlagsgesellschaft, Leipzig, II, 1950, p. 85.Google Scholar
  30. 30.
    Labowitz, L.C., and E. F. Westrum, Jr., J. Chem. Phys., 65, 403 (1961).CrossRefGoogle Scholar
  31. 31.
    Chang, Elfreda, unpublished data.Google Scholar
  32. 32.
    Carlson, H. G., unpublished data.Google Scholar

Copyright information

© Plenum Press 1968

Authors and Affiliations

  • Edgar F. WestrumJr.
    • 1
  1. 1.Department of ChemistryUniversity of MichiganAnn ArborUSA

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