Oscillatory phenomena in the Belousov–Zhabotinsky system. Experimental behaviour studied by potentiometric techniques, kinetic steps and an explanation of the oscillations by the D'Alba–Di Lorenzo Model

Abstract

This work gives some experimental results for the Belousov–Zhabotinsky system. We have studied the influence of varying the concentrations of malonic acid, cerium sulphate and potassium bromate and of varying the rate of stirring in the three periods of oscillation in the system studied: (1) rapid cerium(IV) production, (2) slow cerium(IV) consumption, a steady-state level of cerium(IV) or slow cerium(IV) production and (3) rapid cerium(IV) consumption.

We demonstrate that bromate is reduced by cerium(III) malonate complexes and by bromide. Oscillating supersaturation of bromine allows bromate to shift from steps with bromide to steps with cerium(III) malonate complexes and vice versa. We also show the kinetic steps involved and the agreement between them and our experimental results.