A study on volumetric and compressibility properties of some lithium salts in N,N-dimethylacetamide at 25°C

Abstract

Apparent molar volumes (ϕ_v)<i> </i>and apparent molar adiabatic compressibilities (ϕ_k)<i> </i>have been determined for solutions of some lithium salts (Li Cl, LiBr, LiI, LiClO₄, LiBF₄) in N,N-dimethylacetamide at 25°C from density and sound velocity measurements. Limiting apparent molar volumes (ϕ_v⁰)of the salts have been obtained from ϕ_v vs √<i>c</i> curves and separated into ionic contributions. The apparent molar compressibilities at infinite dilution, ϕ_k⁰have been evaluated by filling ϕ_k against √<i>c</i> by the method of least squares and also the ionic values reported. The results indicate that as the size of the anion increases (cation being the same) electrostatic solvation has an increasing tendency and compressibility of the solution decreases more. The data have been quantitatively explained in terms of solute-solvent interactions along with the degree of disorder in the solvent structure.