A NEW EXPLANATION OF THE OSCILLATIONS IN THE BRAY-LIEBHAFSKY REACTION

Over 70 years ago, Bray discovered oscillations in iodine concentratio n during the iodate-catalyzed disproportionation of aqueous hydrogen p eroxide. Although at least 50 papers have been published about this re action, the mechanism has not been definitively established. We have n ow observed, apparently for the first time, that oscillations can be i nhibited by very rapid stirring. The frequency can also be slowed grea tly by sonication. We believe that transport of oxygen from supersatur ated solution to surrounding atmosphere must be included in any detail ed mechanistic explanation of the oscillations. We propose a skeleton mechanism which appears to explain at least most of the observed behav iors. Additional experiments are proposed which should either support or discredit the proposed new mechanism.