Kinetics and Mechanism of Oxidation of D-Galactose and D-Maltose with Potassium Permanganate in Acidic Medium by Spectrophotometry

Abstract

Oxidation of D-galactose and D-maltose with permanganate ion (MnO₄^–) as oxidant was observed in acidic medium by visible spectrophotometric method. The rate of reaction was followed by the change in absorbance of oxidant at λ_max 545 nm. The influence of different experimental parameters, such as change in concentration of D-galactose and D-maltose, MnO₄^–, H⁺ and reaction temperature were investigated. The oxidation reaction was observed identical first order kinetics with respect to substrate and permanganate ion. A positive effect of H⁺ was found whereas change in ionic strength (μ) has no effect on oxidation velocity. It was observed that rate of oxidation of maltose was much slower in absence of catalyst which was increased after the addition of mercuric acetate while in case of galactose reaction proceeds with out catalyst. The reaction were investigated at different temperatures to evaluate various activation parameters. A suitable mechanism consistent with experimental finding has been proposed.