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1997
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September
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Research: Science and Education
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The Gibbs Energy Basis and Construction of Melting Point Diagrams in Binary Systems
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Norman O. Smith
Fordham University, Department of Chemistry, 441 East Fordham Rd., Bronx, NY 10458
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September 1997
Vol. 74 No. 9
p. 1080
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| Abstract |
Melting point diagrams for binary systems are classified into types depending on the extent of miscibility in the liquid and solid states and the existence of maximum or minimum temperatures. The presence of intercomponent compounds or of polymorphism of the components is excluded. Quantitatively, the diagrams are determined mostly by the melting points of the components, their enthalpies of fusion, and the extent of the deviations from ideality of the liquid and solid solutions as expressed by the excess Gibbs energies or activity coefficients of the components. For simplicity, with little sacrifice of accuracy, most of the liquid and solid solutions are treated as regular ( only one parameter being needed to express the deviations from ideality) and the excess entropies of mixing assumed to be zero. Given such data one can, for each type, determine the corresponding diagram. The detailed procedures for doing so are illustrated, and the necessary data for fifteen real and fictitious examples of the various types are provided for further exercise.
See Correction to this article.
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| More Information |
 Citation |
Smith, Norman, O. J. Chem. Educ. 1997 74 1080.
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Keywords |
Physical Chemistry, Phase Transitions/Diagrams, Thermodynamics, Graduate Education/Research, and Intermolecular Forces
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History |
Created:
Last Updated: |
July 28, 1999
June 23, 2005
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Link to Correction added (May 2004).
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| Home > JCE Print > Journal of Chemical Education > Issues >
1997
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September
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1080
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