VAPOR PRESSURES OF AQUEOUS SOLUTIONS OF SILVER NITRATE, OF AMMONIUM NITRATE, AND OF LITHIUM NITRATE

This paper is devoted to the direct determination of the vapor pressures of solutions of the nitrates of silver, of ammonium, and of lithium, at temperatures varying from 30 °C. to 105 °C. and at concentrations varying from 10 to 85 weight % (for lithium nitrate, the limited solubility precluded measurements beyond 65%). From the vapor pressures, the enthalpies of evaporation of water (by a modification of the Clapeyron–Clausius equation), the differential heats of dilution, and the activities of water (as compared with the mole fractions of the solvent) have been calculated. From the results we conclude that the water of hydration of the ammonium and silver ions (if, indeed, these ions are hydrated at all) is very loosely attached, while that of the lithium ion is strongly bound.