Applications of liquid theory to solution systemsand nucleation theory

Abstract

The significant structure theory of liquids has been successfully applied to solution systems and homogeneous nucleation theory. In solution system, the solutes are regarded as having only the solid-like degree of freedom and solvated with solvent molecules. In the application of the theory to aqueous NaCl solution, the partition function is composed of the partition function for water and that for salt. And also the excess free energy term derived from Debye-H$\ddot{u}$ckel theory is added. The thermodynamic properties such as molar volume, vapor pressure, entropy of vaporization, and heat capacity as well as the dielectric constant are calculated over the whole concentration and wide temperature range. The agreement between the theory and experiment is satisfactory. In applying the theory to sodium ammonia solution, we assumed there were four species, i.e., sodium cation, solvated electron, triple-ion, and free electron and equilibria existed between them. Upon these assumptions, we have set up the model explaining the anomalous properties of sodium ammonia solution qualitatively and also quantitatively as well. In the same manner with the aqueous NaCl solution, the partition function for sodium ammonia solution is composed of the partition functions for the four species and also for the Debye-H$\ddot{u}$ckel excess free energy term. Agreements between calculated and experimental values of the thermodynamic quantities, such as molar volume, vapor pressure, partial molar enthalpy and entropy, and chemical potential as well as viscosity are quite satisfactory. In the case of homogeneous nucleation theory, surface tensions, chemical potentials, and densities of various liquids such as argon, nitrogen, helium, ammonia, and water are calculated from the previously well known partition functions. And using these calculated values, the critical supersaturation ratios and radii of the above materials are determined according to the classical Becker-D$\ddot{o...