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 ambient pressure. A significant stirring effect is observed, and it is confirmed that rapid stirring can cause the oscillatory state to be inhibited. It is shown that the rate of interphase transport of I 2 can be greatly influenced by both bubbling and stirring changes. The total iodine concentration in the solution can be significantly depleted in such a way, and the value of the pseudo rate constant k obs = 3.2 × 10 -4 s -1 for the I 2 removal is determined to be crucial in our set up at 50 °C. This critical value of the rate constant corresponds to the mass-transfer coefficient k tr = 1.60 × 10 -3 cm s -1 . We suggest that the rate of transport of volatile iodine from the BL solution to the gas phase may be a significant component of the overall mechanism of the BL oscillations.