An investigation on ion association and ion solvation of potassium acetate in alcohol solutions

Abstract

The molar conductivities (Λ) of potassium acetate in methanol (MeOH), ethanol (EtOH), 1-propanol (PrOH), 2-propanol (isoPrOH), 2-methyl-1-propanol (MPrOH), 1-butanol (BuOH), 1-pentanol (PeOH), and benzyl alcohol (BeOH) were measured at 293.15 K. The concentration dependence of Λ was analysed by means of the Lee–Wheaton conductivity equation in the form proposed by Pethybridge and Taba. From the analysis of the experimental Λ values, the limiting molar conductivities (Λ_o) and the association equilibrium constants (κ _α) were determined. The centre-to-centre distance (a) of the formed ion pairs were assumed to be equal to the Bjerrum's distance of closest approach. Furthermore, the ultrasonic velocities (u) and the densities (ρ) were measured in order to determine the limiting partial molar volume (V _ϕ ^o) and the limiting apparent isentropic compressibility ( ). The results provide information regarding the association and solvation of the ions of the investigated electrolyte.