Bromine perbromic acid

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. 

The best known exceptions to the general reluctance of bromine to accept a +7 oxidation state are perbromic acid and the perbromate ion, which were unknown prior to 1968 (see Chapter 17). Their subsequent synthesis has made their nonexistence" somewhat less cnicial as a topic of immediate concern to inorganic chemists, but bromine certainly continues the trend started by arsenic and selenium. Thus the perbromate ion is a stronger oxidizing agent than either perchlorate or periodate. 

There is some reason to think that bromine forms bleaching compounds, which, like those of chlorine, contain peculiar acids bromons or hypobromous acids and it is also probable that there exists a perbromic acid, analogous to perchloric acid. Our knowledge of these compounds, however, is very limited. 

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. 

Bromate ions are stable and hence do not disproportionate into perbromate ions and bromine or bromide ions in acidic medium (see Fig. 19.6). 

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