Bromates

The bromine anion

In chemistry, bromates are the salts and esters of the bromic acid HBrO ₃ with the anion BrO ₃^- . The bromine in these compounds has the oxidation state + V.

They are formed by disproportionation of bromine in hot alkaline solutions (50-80 ° C) or by oxidation of hot alkaline bromide solutions with chlorine :

{\ displaystyle \ mathrm {3 \ Br_ {2} \ + \ 6 \ OH ^ {-} \ longrightarrow \ BrO_ {3} ^ {-} \ + \ 5 \ Br ^ {-} \ + \ 3H_ {2} O}}

{\ displaystyle \ mathrm {Br ^ {-} \ + \ 3 \ Cl_ {2} \ + \ 6 \ OH ^ {-} \ longrightarrow \ BrO_ {3} ^ {-} \ + \ 6 \ Cl ^ {- } \ + \ 3 \ H_ {2} O}}

Similar to chlorates or iodates , bromates are strong oxidizing agents . This property is used in bromatometry , a redox titration .

Bromates can arise in drinking water treatment during the oxidation of bromide-containing waters with ozone . Since bromates are carcinogens , this reaction is undesirable and there is a limit value in the Drinking Water Ordinance . This can limit the dosage of ozone. When using chlorine and chlorine dioxide to disinfect drinking water, no bromate is formed, but the chlorination of organic material in the water can lead to the formation of chlorinated hydrocarbons .

Individual evidence

↑ M. Belluati, E. Danesi, G. Petrucci, M. Rosellini: Chlorine dioxide disinfection technology to avoid bromate formation in desalinated seawater in potable waterworks . In: Desalination. The international journal on the science and technology of water desalting , Vol. 203 (2007), Issue 1–3, pp. 312–318 ( PDF ( Memento of July 13, 2007 in the Internet Archive )).

[1] M. Belluati, E. Danesi, G. Petrucci, M. Rosellini: Chlorine dioxide disinfection technology to avoid bromate formation in desalinated seawater in potable waterworks . In: Desalination. The international journal on the science and technology of water desalting , Vol. 203 (2007), Issue 1–3, pp. 312–318 ( PDF ( Memento of July 13, 2007 in the Internet Archive )).