EFFECT OF A GAS BUBBLING AND STIRRING ON THE OSCILLATING BRAY-LIEBHAFSKY REACTION

A sufficient stream of nitrogen or oxygen bubbled into the oscillating Bray-Liebhafsky (BL) reaction system can suppress oscillations at amb ient pressure. A significant stirring effect is observed, and it is co nfirmed that rapid stirring can cause the oscillatory state to be inhi bited. It is shown that the rate of interphase transport of 12 can be greatly influenced by both bubbling and stirring changes. The total io dine concentration in the solution can be significantly depleted in su ch a way, and the value of the pseudo rate constant k(obs) = 3.2 x 10( -4) s(-1) for the It removal is determined to be crucial in our set up at 50 degrees C. This critical value of the rate constant corresponds to the mass-transfer coefficient k(tr) 1.60 x 10(-3) cm s(-1). We sug gest that the rate of transport of volatile iodine from the BL solutio n to the gas phase may be a significant component of the overall mecha nism of the BL oscillations.