Chiotti integration of Gibbs‐Duhem relation and unequivocal determination of limiting partial thermodynamic quantities at infinite dilution of binary solution system

Abstract

AbstractChiotti has made a breakthrough in the thermodynamic theory of solution after nearly a century of frustration. Activity α,i, activity coefficient γi, Darken function αi = In γi/(l‐xi)2 and other partial thermodynamic quantities \documentclass{article}\pagestyle{empty}\begin{document}$ \Delta \bar Q_i^{{\rm{xs}}} \;{\rm{and}}\;\Delta \bar Q_i $\end{document}, where i = Bi and Sn, of binary liquid Bi‐Sn alloy solution system are critically assessed by means of the authentic Chiotti integration, as all those quantities oscillate along composition which made their procurement through classical routes, Gibbs‐Duhem and Darken integrations, impossible. The unambiguous partial quantities at their infinite dilution are obtained from the genuine Chiotti slopes. Interrelations among partial quantities in terms of composition and temperature are presented in detail. We reveal that the apparent Raoultian and Henrian α, vs. Xi behaviors are false and then demonstrate neither Bi nor Sn complies with the Raoult's law and Henry's law. The molten Bi‐Sn system is the athermal type but the behavior of the solution is rather complex and it is definitely neither subregular nor regular solution. In this context the subregular and various symmetrical solutions are systematically developed in relation to function αi and discussed in great detail. A new method of classification of complex solution systems beyond subregular and regular in terms of the difference quantities \documentclass{article}\pagestyle{empty}\begin{document}$ (\Delta \bar Q_B^{{\rm{xs}}} {\rm{-}}\Delta \bar Q_A^{xs} ) $\end{document} is proposed.