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

Abstract

The acid–base equilibria of 1-(2-hydroxyphenyl)ethanone (HY) were studied, at 25 °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 × 10⁻³ mol/kg to 20 × 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 ⇄ Y⁻ + H⁺, log K°_1-1 = − 10.11 ± 0.05 and 2 HY ⇄ HY₂ ⁻ + H⁺, log K°_2–1 = − 7.85 ± 0.05. The uncertainties were given as 3σ. The interaction coefficients (kg/mol) of ionic species Y⁻ and HY₂ ⁻ with the medium counter ion were ε (Y⁻, Na⁺) = 0.50 ± 0.05 and ε (HY₂ ⁻, Na⁺) = 0.59 ± 0.05, respectively.

Graphical abstract