thermochimica acta ELSEVIER ThermochimicaActa 268 (1995) 105-120 Calculation and refinement of thermodynamic parameters from thermometric titrations. II. The neutralization enthalpies of phenols in hydro-alcoholic media R. Forteza *, A. Caro, J.M. Estela, V. Cerd~t Department of Chemistry, University of the Balearic Islands, E-07071 Palmade Mallorca. Spain Received 3 May 1993;accepted 15 April 1995 Abstract Several monoprotic and polyprotic phenols were analysed by thermometric titration in a 50:50 v/v methanol/water medium. The performance of various methods for the calculation and refinement of thermodynamic parameters from thermometric titration data in the determi- nation of the neutralization enthalpies of several phenols in hydro-alcoholic media is compared in terms of precision and the influence of the medium on the titration errors. Keywords: Hydro-alcoholic media; Neutralization enthalpies; Phenols; Thermometric titration 1. Introduction Thermometric titrations are widely used for the determination of inorganic acids, carboxylic acids and phenols in both aqueous and non-aqueous media I-1-6]; more- over, they allow the alkalimetric titration of even very weak acids [ 1]. In addition, they provide precise A H, A G (p Ka) and A S values for ionization processes in an expeditious manner. Non-aqueous and mixed solvents offer well-known advantages in the titration of acids and bases. Were the enthalpy of the reaction not so adversely affected by the nature of the solvent, it could make rather a useful measurement parameter in thermometric titrations since fairly low heat capacities result in steep slopes in the titration graphs. This effect was investigated in earlier papers, where the influence of the * Correspondingauthor. 0040-6031/95/$09.50© 1995- ElsevierScienceB.V.All rights reserved SSDI 0040-6031(95)02435-2