Conductance studies of aqueous solutions of sodium salts of selected benzoic acid derivatives at temperatures from (288.15 to 318.15) K

摘要

The electrical conductivities of aqueous solutions of sodium salts of benzoic acid, 2-hydroxybenzoic (o-salicylic) acid, 3-hydroxybenzoic (m-salicylic) acid, 4-hydroxybenzoic (p-salicylic) acid, 3,4-dihydroxybenzoic (protocatechuic) acid, 4-hydroxy-3-methoxybenzoic (vanillic) acid and 4-hydroxy-3,5-dimethoxybenzoic (syringic) acid were measured over a temperature range (T) of 288.15 to 318.15 K and a concentration range (c) of similar to 1 . 10(-4) to similar to 1.5 . 10(-2) mol.dm(-3). The results were analyzed with Barthel's low concentration Chemical Model (IcCM) to obtain the ionic association constants (K-A(o)) and the limiting molar conductivity (Lambda(o)(m)) of the electrolytes. The limiting ionic conductivity and hydrodynamic radius of the investigated anions were determined, as well as the value for Eyring's activation enthalpy of charge transport. The study also analyzes and discusses the influence of hydrolysis of the salts on their limiting molar conductivity. (C) 2019 Elsevier B.V. All rights reserved.