On the Krichevskii parameter of solutes in dilute solutions: Formal links between its magnitude, the solute-solvent intermolecular asymmetry, and the precise description of solution thermodynamics

We present a novel approach for the calculation of the Krichevskii parameter A(Kr) of solutes in dilute mixtures according to a universal thermodynamic expression that links the solute-solvent intermolecular asymmetry, as described by the Henry's law constant of the solute species in a pure solvent, to the desired A(Kr). The derived expression obeys two key thermodynamic constraints, i.e., corresponding to the behavior of either an ideal gas solute or a solute behaving as a solvent species representing a special case of Lewis-Randall ideal solution. Then, we provide a comparison between the thermodynamically consistent A(Kr) values generated by this approach and those reported in the literature, from diverse experimental sources, and for a variety of aqueous solutes. Finally, we discuss how the A(Kr) = 0 line divides the P - T plane of the pure solvent into two regions characterized by unambiguous solute-solvent intermolecular asymmetries, and provide additional microscopic as well as macroscopic interpretations for A(Kr). (C) 2020 Elsevier B.V. All rights reserved.