THERMODYNAMICS OF IONIZATION OF O-FLUORO AND O-CHLORO BENZOIC-ACIDS IN WATER-ETHANOL MIXTURES AT 298.15 K

The ionization enthalpies of Delta H degrees of o-fluoro and o-chloro benzoic acids were measured by LKB 2277 BioActivity Monitor at 298.15 K in water-ethanol mixtures from pure water up to 0.8 weight fraction ethanol. The ionization-free enthalpies Delta G degrees of the two aci ds in the same mixtures were obtained from published literature. The c orresponding entropies Delta S degrees of ionization were calculated f rom the values of Delta H degrees and Delta G degrees. (C) 1998 Elsevi er Science B.V.