Ultrasonic studies in electrolyte solutions. Part III. The hydration numbers of some acids, alkalis, and tetra-alkylammonium salts

Abstract

Hydration numbers at infinite dilution derived from ultrasonic data are given for the solutes HCl, HNO₃, CH₃CO₂H, NaOH, KOH, LiOH, (CH₃)₄NBr, (C₂H₅)₄NBr, and NH₄Br. The hydration numbers of the acids are lower than expected, whilst those for the tetra-alkylammonium salts are large. The values obtained are explained in terms of a disturbance of the water structure by the ions.