An extremely sharp minimum has been found on the pH versus time curves in the iodate-sulfite-thiosulfate system in a limited range of initial concentrations of the reactants in a static system, while sustained oscillation in pH occurs in a CSTR. This system seems to be the simplest chemical oscillator that can be described by two empirical rate laws, one acid-base equilibrium, and the flow terms. For the extremely sharp change of pH the catalytic effect of thiosulfate on the iodate oxidation of sulfite and the inhibiting effect of sulfite on the oxidation of thiosulfate by iodate are responsible. No explanation could be offered for the extreme temperature sensitivity of the oscillatory behavior in the flow system.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry