CORRELATION BETWEEN DEAGGREGATION OF DYESTUFFS AND THE POLARITY OF THE MEDIUM

From the conductivity measurements on some reactive procion dyes in so lutions containing different mole fractions of ethanol, pyridine or di oxane-water mixtures at 25-degrees-C, equivalent conductance, LAMBDA, degree of dissociation, alpha, dissociation constant, K(D), and the tr iple ion formation constant, K3 were calculated. In non-aqueous medium , LAMBDA diminishes with increasing dye concentration. The free energy for the dissociation process was also evaluated. Detailed explanation was offered on the light of various factors affecting the conductance of solvated dye species by estimating the solvation radii, partial mo lar volume, and van der Waals volume as a function of the polarity of the medium.