. On a mesure la conductibiliG klectrique de 19 electrolytes 1-1 MX (M = alcalin, ammonium quaternaire; X = halogenure perchlorate, nitrate) dans les melanges eau-hexamethylphosphotriamide B 25°C. A I'aide de I'hypoth6se de I'dquimobilit6 des ions dam Bu4NBPh4, on a d6duit les conductibilites individuelles pour 17 ions monovalents dans ces melanges. Aprks une critique des m6thodes traditionnellement utilisees, nous montrons que seule la theorie de Zwanzig permet, B partir de ces rksultats, d'aborder objectivement le probl6me des interactions ion-solvant. Cependant, cette theorie ne permet pas, dans 1'6tat actuel de son developpement, d'elucider la totalite des probl6mes puisque Zwanzig considkre le dkplacement de I'ion nu mais elle permet de bien distinguer, selon la mobilite d'un ion, la nature des interactions entre celui-ci et le solvant.
JEAN-YVES GAL, CHRISTINE LAVILLE, FRAN~OISE PERSIN, MICHEL PERSIN, JEAN-CLAUDE BOLLINGER, and TH~OPHILE YVERNAULT. Can. J. Chem. 57, 1127 (1979).The electrical conductibilities of 19 1-1 MX electrolytes (M = alkaline, quaternary ammonium; X = perchlorate, halide, nitrate) in water-hexamethylphosphotriamide mixtures at 25°C has been measured. The individual conductibilities of 17 monovalent ions in these mixtures were calculated using the hypothesis of ion equimobility in Bu4NBPh4. Following a critical review of the traditionally used methods, it has been shown that, from these results, Zwanzig's theory alone allows the objective assessment of ion-solvent interactions. However, this theory at its present state of development cannot be used to elucidate all the problems (because Zwanzig considers the displacement of the free ion) but it does distinguish the nature of the interactions between an ion and the solvent, depending on the mobility of that ion.