Kinetics of hydrolysis of diperiodatoargentate(III) ion and its reduction by paracetamol

The kinetics of hydrolysis and reduction of the diperiodatoargentate(III) ion (DPA) has been studied in aqueous acidic medium spectrophotometrically. Upon dilution the silver (III) complex was found to be unstable in the presence of H2O. Addition of [H+], largely increased the hydrolysis rate, whereas [OH-] does not have any effect. Under pseudo-first-order conditions ([paracetamol] > [DPA]), the reduction rate was very fast. Second-order conditions were used to determine the reaction rate. The reaction was acid-catalyzed and the rate decreased by the addition of periodate. The Arrhenius equation was valid for the reaction. The changes observed in the direction of the rate constant-[H+] profile correspond to aquation of the diperiodatoargentatate(III) complex. The proposed mechanism and the derived rate law are consistent with the observed kinetics.