First and second dissociation constants and related thermodynamic functions of adipic acid in various binary methanol/solvent systems.
The First and second dissociation constants of adipic acid were determined by EMF measurements in water/methanol mixtures with 0, 30, 50 and 70 wt% organic cosolvent. Measurements were made at four different temperatures (ranging from 30 to 60 degrees C) using the cell: glass electrode/HCL (m(1)), H(2)L (m(2)), Na(2)CO(3) (m(3))/AgCl ((S)), Ag. The computations of these dissociation constants were based on the method of successive approximation by means of basic programmes. The thermodynamic properties (DeltaG degrees , DeltaH degrees and DeltaS degrees ) for first and second dissociation reactions of the acid under study, were computed, analyzed and discussed in terms of solute-solvent interactions.
El-Naggar
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Chemistry Department, Faculty of Education, (Damanhour Branch) Alexandria University, P.O. Box 426 Ibrahimia, Alexandria 21321, Egypt.