Vapour pressures of saturated aqueous solutions of NH4I, KI, KNO3, SrCl2, Li2SO4, Na2S2O3, Mg(NO3)(2), and UO2(NO3)(2) were determined in the temperature range (278 to 323) K using an electronic hygrometer with an electrolyte sensor, and compared with literature data. Water activities, osmotic coefficients, and molar enthalpies of vaporization and solution at saturation point were evaluated from the determined vapour pressures.