Phenolphthalein Indicator in Titrimetric Estimation of Benzoic Acid Solubility and Distribution in Water and Benzene-Buffer Solutions

Abstract

In solubility and partitioning process of benzoic acid, the various factors are involved such as temperature, solute-solvent interaction and dissociation of acid into ionic state in taking solvents. Here, we reported the benzoic acid (solute) solubility in gram/100gram of solvent in different pH benzene-buffer solutions which are analyzed by using of titration method and partition study of these acid into solvents like water and benzene layer by shake-flask acid-base titration method, at room temperature (25°C) for 24 hours. In titrimetric estimation the solute benzoic acid solubility and their partition in between of water and in different pH buffer solutions as in medium of acidic, neutral and basic, a phenolphthalein indicator have been used well. The solvents and benzene-buffer solutions having different pH 4.0, 7.0 and 9.0 is titrated against as 0.01, 0.05 and 0.1N NaOH solutions by using phenolphthalein as indicator, where the end point show a pink color for each reading. Concentration of benzoic acid into water and solvent benzene layers is being calculated as by applying the equation of normality determination and distribution coefficient as from Nernst distribution law equation.