The kinetics of oxidation of carboxymethyl cellulose (CMC) by permanganate ion in aqueous perchloric
acid at a constant ionic strength of 2.0 mol dm3 has been investigated, spectrophotometrically. The reaction
time curves of the pseudo first-order plots were of inverted S-shape throughout the entire course of
reaction. The initial rates were found to be relatively slow in the early stages, followed by an increase in
the oxidation rates over longer time periods. The experimental results indicated first-order kinetics in
permanganate and fractional second-order dependence with respect to CMC concentration in either
the induction or autoacceleration periods. Kinetic evidences for the formation of 1:2 intermediate complexes
were revealed in both stages. The influence of the [H+] on the reaction rates showed that the oxidation
reactions are acid-catalyzed in both stages. Added salts indicated that MnIII and/or MnIV play an
important role in the reaction kinetics. The kinetic parameters have been evaluated and a reaction mechanism
consistent with the experimental kinetics is suggested