Bistability and Oscillations in the Autocatalytic Chlorite-Iodide Reaction in a Stirred-Flow Reactor

Abstract

The reaction between chlorite and iodide in acidic solution (0.08 < pH < 3.75) has been studied in a stirred-tank reactor at 25 “C over a range of flow rates, pH, and input chlorite and iodide concentrations. The system is found to exhibit bistability and, at high [ClO2−] and [I−], sustained oscillations as well. The key reaction which gives rise to these phenomena is ClO2− + 4I− + 4H++ = Cl− + 2I2 + 2H2O, which is autocatalytic in iodine and is inhibited by iodide. The existence of bistability and oscillations in this system is consistent with the “cross-shaped phase diagram” model of Boissonade and De Kepper. © 1982, American Chemical Society. All rights reserved.