The Electrostatic and Non-Electrostatic Interaction Affect on Acidity Constants of Bromocresol Purple in Aqueous Ethanolic Media

This work aimed to the study effect of ethanol ratios on acidity constants bromocresol purple. The BCP were determined in binary mixtures water with containing 0, 30, 40, 50, 60, and 70% (v/v) using spectrophotometric methods. results indicate dependence ratio ethanol. values log10Ka1 log10Ka2 correlated macroscopic (relative permittivity, ε) microscopic Kamlet–Taft parameters (α, β, π*) mixtures. influence solvent was analyzed terms KAT order solvent–solute interaction. Multiple linear regression used find contribution α (acidity), π* (dipolarity/polarizability), β (basicity). It found that hydrogen bond donating accepting abilities most predominant change constants. Also, a relationship reciprocal relative permittivity obtained based Born’s model. bonding interactions between solute components are mainly responsible for purple