Thermodynamic properties of solutions are not only useful for estimation of feasibility of chemical reactions in solution, but they also offer one of the better methods of investigating the theoretical aspects of solution structure. The physico-chemical properties involves the interpretation of the excess properties as a mean of unraveling the nature of intermolecular interactions among the mixed components. The excess properties such as excess molar volume, viscosity deviations and deviation in isentropic compressibility along with the correlating equations explain molecular interactions in a more effective way. A knowledge of ion-solvent interactions in non-aqueous solutions is very important in many practical problems concerning energy transport, heat transport, mass transport and fluid flow. This monograph embraces a series of investigations based on the volumetric, viscometric, interferometric and conductometric behaviour to study the chemical nature of the structure of solutes and solvents and their mutual and specific interactions in solution.