KINETICS AND EQUILIBRIUM OF THE DEHYDRATION-HYDRATION AND RECOMBINATION-DISSOCIATION REACTIONS OF GLYOXYLIC-ACID INVESTIGATED BY ELECTROCHEMICAL METHODS

Equilibrium constants of the glyoxylic acid hydration have been define d more precisely taking into account the values of the DC polarographi c limiting kinetic current and the dimerization effect. For the correc t calculation of the rate constants for the glyoxylic acid dehydration and recombination reactions, the diffusion contribution of the dehydr ated anions into the limiting kinetic current of the first and total D C polarographic waves was considered and the concept of the preceding consecutive rate determining reactions of the dehydration and recombin ation was used. The rate constants from the DC polarographic data have been obtained that are close to the ones from the pulse polarographic and spectrophotometric data. On the basis of a comparison with the li near-sweep voltammetric data, intermolecular catalysis of the dehydrat ion reaction was noted. The recombination stage corresponds to protona tion of the carboxylate group. The fast intramolecular protonation of the carbonyl group after the recombination stage has been considered.