The study has been devoted to the search of adequate models for describing ionic equilibria with the help of conductance in aprotic media with low and medium dielectric permittivity. The salts of the picric acid have been chosen for this research, namely, tetra-n-butyl, tetraethyl, cetyltrimethyl, N-cetylpyridinium, and potassium picrates. In the most cases, the mixtures of acetone with n-butylacetate and n-hexane have been used as solvents. Using tetra-n-butylammonium picrate and acetone-n-butylacetate and acetone-n-hexane as examples of an electrolyte and solvents with of 20,56 to 4,99 respectively, the model was developed for describing ionic equilibrium within the concentration range of 0,3 10-4 to 7,8 10-2 М. This model unifies the approach by Hojo and the Lee-Wheaton equation. At ? 7, the existence of ionic triplets is necessary for adequate description of the equilibria, whereas the phoreograms at = 8,8 - 9,1 may be interpreted practically equal either with taking inter the consideration the ionic triplets or without them. On the drop of the polarity up to < 7, the decrease in the Walden product has been revealed. For media with low values, a procedure for additional checking of the correctness of the joint calculation of the association constants of ion pairs, triplets, quadruples, and limiting conductivities has been developed. The approach consists in the extrapolation of the linear dependence in the given binary mixtures to the low values. In binary mixed solvents with = 9,07 and 12,54, the association constants of picrates with the cations K+ and n-Bu4N+ have been estimated via the spectrophotometric method. These values coincide with those determined by conductance. The shift of the absorption band of the picrate anion originating from the association with metal cations makes up 20 nm or even more, and a new maximum, typical for ionic associates, appears. According to the influence of the inorganic salts upon the band position of picrates, the cations may be arranged in the following sequence: Th4+ > La3+ > Mg2+ > Li+ > Na+ > Pb2+.
