Thermodynamic study of the ternary system Th(NO3)4/HNO3/H2O

A method is presented for calculating the stoichiometric activity coefficients of the components of a ternary mixture, regardless of its composition. This method is based on i) the concept of simple solutions and ii) the use of the measurement of water activity of a ternary mixture. An application relative to the ternary mixture Th(NO3)4/HNO3/H2O is developed. These results show the importance of the effects of deviation from simple solution behavior in the calculation of electrolyte activities in a ternary mixture at high ionic strength. (orig.)