Modeling of interactions between iodine interphase transport and oxygen production in the modified Briggs-Rauscher reaction with acetone.
Novel aspects of influence of gas evolution on oscillating chemical reaction are considered on a model of the modified Briggs-Rauscher reaction with acetone. The mechanism proposed by Noyes with Furrow and De Kepper with Epstein, adapted for acetone and expanded with oxygen evolution and first-order escape of iodine by interphase transport, was subjected to further extension, and calculations assuming direct proportionality of the rate of iodine escape on the surface area of the oxygen gas trapped in the solution as well as calculations considering first-order back-flow of iodine from the gas phase into the solution were performed. Furthermore, the concentrations of iodine vapors were considered to be variable within the bubble population, as all the bubbles are not in contact with the reaction mixture for the same length of time. Distribution functions of the surface size over the range of concentrations of iodine in the contacting gas phase were introduced and derived, and whereas they were proved not to play any role in the total intensity of iodine return when it is first-order, the article also demonstrates their explicit consideration in calculations to be essential if the dependence of the rate of iodine return into the solution on its concentration is not linear, for example, in future extensions of the model with bubble radius also considered variable.
Szabo
Erik
E
Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovakia.
Sevcík
Peter
P