Vapour pressures of aqueous solutions of AgNO3 + TlNO3 by the static method at 98.5 °C

Abstract

Vapour pressures of the system (Ag,Tl)NO3 + H2O have been measured at 98.5 °C by the static method over the complete concentration range for Ag/Tl mole ratio = 1.14. The water activity data can be represented by a modified BET isotherm in the range 0.1 < aw < 0.7. The derived BET constants indicate that the salts in this system are very weakly hydrated, probably less so than (for example) CsNO3. The linearity of vapour pressure with water mole ratio RH, found previously by Tripp and Braunstein for (Li,K)NO3 + H2O, is absent in the present system. The Henry's law constant for water dissolved in molten (Ag,Tl)NO3 has been deduced. The excess free energy of the system is positive at all concentrations and shows a maximum of 117 cal/mol at water mole fraction 0.66.