Topic description and teaching suggestions: Equilibrium calculations are an important tool to predict the phases which are stable under given conditions and to predict their composition. The availability of thermodynamic data banks for gaseous species and condensed phases is most important. The lack of necessary information is a particularly critical problem for high-temperature scientists. Knowledge of the entropy, enthalpy and free energy changes associated with a chemical process is important in many areas of chemistry. There are many sources of thermochemical data compiled in different forms that can be used effectively for the given purpose. These data bases must be prepared by qualified people. There may be significant discrepancies in the assessed values of different databases, depending on the chemical system, and one has to use criticism and to make efforts to reconcile these. In teaching students, a warning should be made in the selection of database to be used for equilibrium calculation and modelling. However, because of both the demanding nature of experimental thermodynamics especially at high and very high temperatures and the enormous number of conceivable compounds, reliable experimental data are often unavailable or impossible to obtain. Empirical predictive models and, more recently, theoretical approaches (like DFT) are being used effectively for generating thermodynamic data which complement or supplement experimental data in generating extensive databases.
Web and electronic sources, compilations of data
IVTANTHERMO for WINDOWS - Thermodynamic Database and Thermodynamic modeling Software. Version 3.0. Glushko Thermocenter of Russian Academy of Sciences. http://www.openweb.ru/thermo/index_eng.htm. R. Hultgren, P.D. Desai, D.T. Hawkins, M. Gleiser, K.K. Kelley, D.D. Wagman, Selected Values o f t h e T h e r m o d y n a m i c P r o p e r t i e s o f t h e E l e m e n t s , ( 1 9 7 3 ) A m e r i c a n S o c i e t y f o r M e t a l s :
Metals Park, OH, USA.
SGTE databases. Scientific Group Thermodata Europe. http://www.sgte.org/
http://www.nist.gov/srd/thermo.htm, and in particular http://webbook.nist.gov. Among NIST compilations covering thermodynamic data for inorganic substances, see the last edition of