Abstract
The conductivity of silver nitrate at 25°C and 30°C has been studied in pure methanol and binary solvent mixtures containing 99°9 per cent methanol and 0.1 mole per cent of an organic liquid of the type which exhibits a strong affinity for silver ions. The results have been interpreted in the light of modern electrolyte theory, and values of the association constant, equivalent conductance at infinite dilution, Stokes' radius and the Fuoss "a" parameter have been calculated. The heat, free energy and entropy of ionisation in a number of solvents were calculated from the corresponding association constants at 25°C and 30°C. From a consideration of the concept of solvent structure breakage in the vicinity of ions, the variation of association with the distance of closest approach of oppositely charged ions as predicted fey the theory of Fuoss, and the theory of kinetics of ionic equilibria, it has been suggested that the dielectrio, constant value of the medium in the vicinity of silver ions in solvent-mixtures of the type investigated is probably different from the corresponding bulk value. The constants obtained from the investigation of the conductivity of silver nitrate in methanol containing 0.1 mole per cent benzene at 25°C and 30°C indicate that benzene does not form a stoichiometric complex with the silver ion. It has been suggested that the interaction between benzene and the silver ion is of a longer range type than that met with in permanent solvation and that benzene molecules form loose aggregates in the neighbourhood of silver ions.