INFLUENCE OF THE SOLVENT ON THE CONCENTRA TION-DEPENDENCE OF THE MOLAR VOLUME AND OF THE ELECTRICAL-CONDUCTIVITY OF ELECTROLYTE-SOLUTIONS

The systems investigated in this work are composed of the ternary eute ctic mixture NH4NO3-NH4Cl-LiNO3 (66.7:9.5:25.8 mol. %) on the one hand and of ethylene-glycol, formamide, dimethylformamide or dimethylsulfo xide on the other hand. The influence of the composition of these mixt ures on their molar volume and on the electrical conductivity has been evidenced. At high electrolyte concentration, the composition depende nce of the molar volume is explained by the exclusive localisation of the molecular compound in the solvation shell of the ions. The compari son of the conductivity isotherms points out the influence exercised b y the dimensions and by the shape of the molecules of the non-electrol yte on the ionic mobilities.