Bromous acid

Positive bromination was first observed by Shilov and Kaniaev189 who found that the bromination of sodium anisole-m-sulphonate by bromine-free hypo-bromous acid was accelerated by the addition of nitric or sulphuric acids, and was governed by the kinetic equation... 

Al-Bromosuccinimide (NBS), 13 116 brominated butyl rubber from, 4 434 bromination reagent, 4 344 Bromothymol blue, 4 362t Bromotrichloroethane, 6 269 Bromotrifluoromethane, 4 348, 348t Bromous acid, 4 333... 

In aqueous solution, bromine hydrolyzes shghtly, forming unstable bypo-bromous acid, HOBr, which decomposes to hydrobromic acid and oxygen, causing the bleaching action of bromine water. The decomposition is accelerated by light. 

At first, A. J. Balard called tbis substance muride, but afterwards bromine— from the Greek (3pu>iws, a stench. A. J. Balard prepared hydrobromic, hypo-bromous, and bromous acids and he concluded his memoir by summing up the arguments in favour of the elementary nature of bromine ... 

Fig. 15. The relationship between the

Bromous acid disproportionates rapidly, and at high bromate and acid concentration, a fast equilibrium is established between bromate and hypobromous acid [Eq. (23)]. 

Bromates.—The bromates are white salts soluble in water they do not, however, decompose into bromide and perbromate when heated the perbromate is unstable, and bromide and oxygen are the only products. Bromic acid, too, when warmed changes to water, hydrobromic acid, bromine, and oxygen as no compound analogous to C102 is produced, bromous acid is unknown. 

The Belousov-Zhabotinsky reaction scheme can also produce moving spatial inhomogeneties in unstirred solutions. Spatial waves develop as an oxidizing region advances into a region of low but finite bromide ion concentration that falls below a critical value. The autocatalytic production of bromous acid at the interface advances the wave faster than the diffusion of any other molecules proceeds (Field et al., 1972). Nagy-Ungvarai and Hess (1991) used the electrochemical method to produce experimental data on the two-dimensional concentration profile of three variables in distributed Belousov-Zhabotinsky solutions. 

Although bromous acid itself is unknown, Ba(Br02)2 and the corresponding strontium salt can be prepared by treating hypobromite with Bt2 in strongly basic solutions at 0°C, followed by slow evaporation. 

Using the assumptions we ordinarily make in calculating the pH of an aqueous solution of a weak acid, calculate the pH of a 1.0 X 10 6 M solution of hypo-bromous acid (HBrO, Ka = 2 X 10-9). What is wrong with your answer Why is it wrong Without trying to solve the problem, tell what has to be included to solve the problem correctly. 

The bromohydrins, bromoketones, ketones, and alcohols derived from the 22,23-epoxides were also characterized.Stereochemical features of the reactions between the 24-norchol-22-ene system (84) and m-chloroperbenzoic acid, hypo-bromous acid, and osmium tetroxide have also been studied. 

BrHOz HOBrO, hydroxy-X3-bromanone, hydroxidooxidobromine bromous acid ... 

Subsequently bromous acid reacts with bromide ion to yield also hypobromous acid, HBr02 + Br" + H+ -> 2 HOBr (R2)... 

Bromate ion reacts with bromous acid to yield radical Br02 ... 

Then Br02 reacts with cerium(III) ion to yield bromous acid and cerium(IV) ion (= cerium oxidation)... 

Bromous acid breaks down to bromate ion and hypobromous acid,... 

As the concentration of bromomalonic acid, BrCH(COOH)2 increases reaction (RIO) becomes important. The bromide ion, Br produced by (RIO) is destroyed by (R2) as long as the autocatalytic production of bromous acid, HBr02, by the sequence (R4) + 2(R5) is able to maintain bromous acid. The concentration of HBr02 at the value of the second-order destruction of HBr02 by (R6), which creates the steady state is given by... 

The concentration of bromous acid in Process B is over 105 times as great as that in Process A for which the bromous acid attains the steady state given by... 

The variable u describes the local concentration of bromous acid HBr02, the variable v the oxidized form of the catalyst Ru(bpy)3", and w describes the bromide concentration. Here the parameter light intensity, and the photochemically-induced production of bromide is assumed to be linearly dependent on it, d Qv ]/dt(x4> [32]. e, e and q are scaling parameters, and / is a stoichiometric constant [47]. This model can be reduced to the two-component one by adiabatic elimination of the fast variable w (in the limit e e) [47]. In this case one gets the following two-component version of the Oregonator kinetics... 

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