Liquid–Liquid Distribution Study of the Dissociation of Perchloric, Nitric, and Picric Acids in Polar Organic Solvents

The liquid–liquid distribution equilibria of perchioric, nitric, and picric acids between water and 4-methyl-2-pentanone or 4-methyl-2-pentanol have been determined at 298 K by measuring the concentrations of the anions in the two phases by spectrophotometry. The distribution ratio always increased on increase of the acid concentration; this was explained in terms of an increase in the degree of association of the acids in the organic phase. It was concluded from the analysis of the distribution data that the dissociation constant of perchloric acid was the highest and the value of picric acid was higher than that of nitric acid in 4-methyl-2-pentanone. The dissociation constant of picric acid was also higher in 4-methyl-2-pentanol than that of nitric acid; it was similar to that of perchloric acid. The differences of the dissociation constants were larger in 4-methyl-2-pentanone than in 4-methyl-2-pentanol.