The reaction of valine with ceric ion has been kinetically studied in aqueous sulphuric acid medium in the presence of palladium(II) as catalyst using a spectrophotometric method at 45◦C temperature. The reaction was studied under pseudo first order conditions with respect to cerium(IV). The results exhibits first order each in cerium(IV) and palladium(II) and a positive fractional order with respect to [Val]. The rate decreases with the increase of [HSO4-] and increases with increase of [H+]. The stoichiometry of the reaction was found to be 1:2. 2-methylpropanal and Ce(III) were identified as the reaction product. Added products do not have any significant effect on the reaction rate. A suitable mechanism was proposed to account for the kinetic data, so that the rate equations derived for this mechanism could explain all observed results.
Keywords : Kinetics, Mechanisn, Cerium(IV), Valine, Palladium(II) catalysis, Sulphuric acid medium.