Conductivity Studies of Tetrabutylammonium Salts in 1-propoxy-2-propanol: Ion-association in Dilute solutions

The molar conductivities A of n-tetrabutylammonium bromide, n-tetrabutylammonium nitrate, n-tetrabutylammonium thiocyanate and n-tetrabutylammonium acetate solutions in 1-propoxy-2-propanol (PnP) have been measured. The temperature and concentration range covered is from 248.15 to 313.15 K and 0.18 × 10–3 to 6.4 × 10–3 mol L–1, respectively. Accurate viscosity, density and permittivity data were additionally determined for the pure solvent. Data analysis was performed on the basis of the low concentration Chemical Model (lcCM), including short-range forces. Values for the limiting molar conductivities (A∞) and the association constants KA are derived. Thermodynamic results on the ion-pair formation process are discussed in terms of coulombic and non-coulombic forces by an appropriate splitting of the Gibbs free energy.