Mécanisme des réactions du chlorite et du dioxyde de chlore. 5. Cinétique de la réaction chlorite–bromure

Abstract

GUY SCHMITZ et HENRI ROOZE. Can. J . Chern. 65,497 (1987). Dans les solutions acides de chlorite et de brornure on observe sirnultanernent la disrnutation du chlorite et une reaction autocatalytique conduisant une production rapide de C102. Les caractCristiques inhabituelles de cette rCaction sont dCcrites. GUY SCHMITZ and HENRI ROOZE. Can. J. Chem. 65,497 (1987). In acidic solutions of chlorite and bromide two processes occur simultaneously, the disproportionation of chlorite and an autocatalytic reaction leading to a rapid production of C102. The unusual features of this reaction are described. In this complex system the rate of HC102 + Br-+ H+ + HClO + HBrO cannot be measured. It can be, however, with added ortho-tolidine to remove the HBrO and HC10. We obtainedwith k = 1.48 x M-'s-' at 25OC. Without added ortho-tolidine this reaction initiates the autocatalytic reaction for which we suggest a kinetic scheme.

Kinetics and Mechanisms of Bromine Chloride Reactions with Bromite and Chlorite Ions

“…Characteristics of XOXO Molecules. Several authors have proposed the presence of ClOClO , and BrOClO ,, as intermediates in the gas phase and in solution. In the current study we propose BrOClO as an intermediate in the BrCl/ClO 2 - reaction.…”

Kinetics and Mechanism of the Oxidation of Bromide by Periodate in Aqueous Acidic Solution

“…First, involving Cl 2 O 3 as a short-live transient species in the decomposition of chlorous acid is well-established . Second, the strong buffer assistance observed, however, makes this possibility quite likely as well because subsequent reaction of similar intermediates, like Cl 2 O 2 , Br 2 O 2 , and ClBrO 2 , I 2 O 2 , is frequently accompanied by buffer catalysis. ,− Such analogies thus would seem to favor the inclusion of BrIO 3 as a key intermediate in the title reaction. Because the bromonium ion (Br + ) is expected to be a good leaving group from BrIO 3 , we suggest that this species may partially be responsible for bromination of the several organic substances at the molecular level.…”

Multifold Increases in Turing Pattern Wavelength in the Chlorine Dioxide-Iodine-Malonic Acid Reaction-Diffusion System

“…We represent the chlorite-bromide and chlorite-chloride reactions with the −cv term. This term is used to simplify the detailed kinetics of the bromiderelated [21][22][23][24] and chloride-related [25][26][27][28][29] mechanisms into a reaction rate law that is first order in v and first order in halide concentration. Since in our study we use a large excess of bromide and chloride compared to chlorite, we further simplify the expression to a pseudo-first order form.…”