Determination of Water-Ethanol Mixtures Antoprotolysis Constants and Solvent Effect

The autoprotolysis constants (PKap) of water/ethanol mixtures containing 0-90 % v/v ofethanol have been determined at 25 DC and 0.1 M Ionic strength using potentiometricmethod. Ionic strenght of each mixture was maintained by NaCIO4 solution. The results indicate that water-ethanol mixtures are more basic media than pure water and the pKap value of this media increases with addition of ethanol. The influence of the dielectric constant of investigated mixture solvent on the autoprotolysis constant was described employing Yasuda-Shedlovsky procedure.