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.