Perbromates, decompositions

The solid produced at —5°C by interaction of bromine and ozone is only stable at —80°C or in presence of ozone, and decomposition may be violently explosive in presence of trace impurities [1], The structure may be the dimeric bromyl perbromate, analogous to Cl206 [2],... 

Potassium pentafluoroaluminate monohydrate, 2 371 Potassium perbromate, 4 335 Potassium perchlorate, 18 277 Potassium permanganate, 9 635-636 crystallographic studies on, 15 601 as a detoxicant, 15 621 decomposition of, 15 597 as an ignitable waste, 15 615 industrial-scale production of, 15 606 manufacture of, 15 601-606 for purifying carbon dioxide streams, 4 815... 

Though metal perbromates and periodates are known (but not perfluorates), the perchlorates have most frequently been involved in hazardous incidents over a long period. These usually stable salts are powerful oxidants and contact with combustible materials or reducants must be under controlled conditions. A severe restriction on the use of metal perchlorates in laboratory work has been recommended [1], Attention has been drawn, on the basis of experience with cobalt(II) perchlorate, to the possibility of stable hydrated metal perchlorates being converted by unintentional dehydration to unstable (endothermic) lower hydrates capable of explosive decomposition in absence of impurities. Great care to avoid dehydration (or desolvation) is urged [2],... 

The synthesis of HBr04 and rubidium and potassium salts was accomplished, using oxidation of bromate by XeF2 or (preferably) molecular fluorine in aqueous solution.19 Spectral studies20 show that the perbromate ion is tetrahedral in both the solid-state and aqueous solutions. The thermodynamic properties and thermal decomposition of individual salts are discussed under each element. A more general article on various properties of the perbromates was published by Herrell and Gayer.21... 

Perbromic acid is a strong monobasic acid. Its aqueous solutions are stable up to about 6 M (55% HBr04), even at 100°. Fairly concentrated solutions may develop a yellow bromine color from the decomposition of traces of bromate ion and hypobromous acid. If a 6 M perbromic acid solution is allowed to stand for several months, the bromate and hypobromite will have all decomposed, and the resulting bromine can be flushed out with pure nitrogen, leaving a colorless solution. 

Above 6 M, perbromic acid solutions tend to be erratically unstable, although the decomposition is not explosive. Concentration in vacuum at room temperature produces an azeotrope consisting of about 80% perbromic acid (ca. 12 M), which usually decomposes during or shortly after preparation. Molec-... 

Pure potassium perbromate is stable up to 275°, at which temperature it decomposes to potassium bromate. The impure product may undergo partial decomposition at lower temperatures. 

Silver perbromate, AgBr04.—The perbromate is prepared by double decomposition from potassium perbromate and silver nitrate, and is but slightly soluble in cold water. 

Perbromic Acid—HBrO,— 145—is obtained on a comparatively stable, oily liquid, by the decomposition of perchloric acid by Br, and concentrating over the water-bath. 

LD50 (rabbits) 5 mg/kg (NIOSH 1986) produces toxic phosphine on decomposition room temperature explodes when heated rapidly decomposed by water or alcohol to HI and phosphine (ignites) ignites spontaneously with nitric acid and with perchloric, perbromic, and periodic acids ignites in contact with chlorates, bromates, and iodates when dry... 

Solutions of HBr04 can be concentrated up to 6 M without decomposition and are stable for prolonged periods. Some perbromate salts have been isolated and appear to be reasonably stable. Even NH4Br04 can be heated to around 170°C. 

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