Solubility and acidic constants at 25 A degrees C in NaClO4 aqueous solutions of 1-(2-hydroxyphenyl)ethanone

摘要

The acid-base equilibria of 1-(2-hydroxyphenyl)ethanone (HY) were studied, at 25 A degrees C, by potentiometric measurements with a glass electrode in NaClO4 media for ionic strength ranging from 0.51 to 3.5 mol/kg. The solubility (S) of HY was determined in the same range of ionic strength in NaClO4 media. The total concentration (C (L)) of ligand was ranged from 1 x 10(-3) mol/kg to 20 x 10(-3) mol/kg; the experimental data were explained by assuming, for HY, the species HY2 (-) besides Y-. Elaboration of data, according to the specific interaction theory, had provided the constants valid in the infinite dilution reference state: HY a double dagger" Y- + H+, log KA degrees(1-1) = - 10.11 +/- A 0.05 and 2 HY a double dagger" HY2 (-) + H+, log KA degrees(2-1) = - 7.85 +/- A 0.05. The uncertainties were given as 3 sigma. The interaction coefficients (kg/mol) of ionic species Y- and HY2 (-) with the medium counter ion were epsilon (Y-, Na+) = 0.50 +/- A 0.05 and epsilon (HY2 (-), Na+) = 0.59 +/- A 0.05, respectively.