Conductometric and ultrasonic studies on ion-solvent interaction of K⁺ of KCNS in water + methanol/ethanol mixtures

Abstract

The results of the ion-solvent interaction of K⁺, potassium thiocyanate in water + methanol/ethanol and their various mixtures (<i>v/v</i>) at 288, 298, 308 and 313K, using conductivity principle are reported. The solvation number of cation was determined by ultrasonic and mobility methods. Conductivity data were analysed by three major

conductivity models. Limiting molar conductance decreases sharply with increase in co-solvent concentration. Association constant, Walden product, corrected Stoke's radius (<i>r</i>₁) and activation energy (<i>E</i>_a) of rate process were calculated for all solvent compositions and temperatures. Measured viscosity and ultrasonic velocity were used to determine solvation number of potassium ion (K⁺) and is found to be maximum in methanol. The Born relations

were used to compute thermodynamics of solvation. All these data were used to investigate the nature of ion-solvent interaction existing in the system under prevailing conditions.