Abstract
The individual activity coefficients of ions for alkaline halides in the binary systems LiCl‐H2O; NaCl‐H2O; KCl‐H2O; CsCl‐H2O, and in the ternary systems LiCl‐NaCl‐H2O; LiCl‐KCl‐H2O; LiCl‐CsCl‐H2O; NaCl‐KCl‐H2O are calculated on the basis of the data obtained by cryoscopic measurements. The contribution of the ions to the interaction coefficients of the electrolytes in the solutions studied is determined by means of ion activity coefficients.