USE OF CONVOLUTIVE POTENTIAL SWEEP VOLTAMMETRY IN THE CALCULATION OF HYDRATION EQUILIBRIUM-CONSTANTS OF ALPHA-DICARBONYL COMPOUNDS

The applicability of the convolution potential sweep voltammetry to th e calculation of hydration equilibrium constants K(H) for a series of alpha-dicarbonyl compounds is demonstrated. K(H) values for glyoxal, m ethylglyoxal, acetylbenzoyl, 1,2-cyclohexanedione, diacetyl and 3,4-he xanedione are obtained as functions of the temperature. The values of apparent DELTAH and DELTAS are calculated from these constants. The co nsistency of the K(H) values is tested by showing the occurrence of an enthalpy-entropy compensation effect. Hydration reactions are shown t o be enthalpy controlled.