Thermodynamic Studies on Ion Association of Lithium Chloride and Lithium Nitrate in Acetonitrile + Water Mixed Solvents at Different Temperatures

Abstract

The present study reports the ion association of lithium chloride (LiCl) and lithium nitrate (LiNO₃) electrolytes in acetonitrile + water (AN+W) mixtures at 283.15 K to 311.15 K. Their limiting molar conductance (Λ_o), the association constant values (K_A) for their different mole fractions, i.e. 0.0000, 0.0588, 0.1233, 0.1942, 0.2727, 0.3600, 0.4576, 0.5676, 0.6923, 0.8351 and 1.0000 have been evaluated using Shedlovsky technique. The K_A and Walden products (Λ_oh_o) for LiCl and LiNO₃ salts have been calculated in the acetonitrile-water solvent at experimental temperatures. The calculated values qualitatively examined the possible nature of the solvent-solvent, their ion-ion, and ion-solvent and interactions of the two selected compounds mixed solvents of (acetonitrile + water). Then dependence of K_A temperature has also been investigated to obtain the thermodynamic functions of different parameters, such as ΔGº, ΔSº, ΔHº and E_a, as a function of the mixed composition of the composition solvents AN+W (acetonitrile + water).