In the reaction
`3Br_(2) + 6CO_(3)^(2-) + 3H_(2)O to 5Br^(-) + 2BrO_(3)^(-)+6HCO_(3)^(-)`

Options

A. (1) bromine is oxidised and carbonate is reduced
B. (2) bromine is both oxidised and reduced
C. (3) bromine is reduced and wate is oxidised
D. (4) bromine is neither oxidised nor reduced

Answer

B

Explanation

`3Br_2+ 6CO_3^(2-) + 3H_2O to 5Br^(-) + BrO_3^(-) + 6HCO_3^(-)` (disproportionation reaction )
In this reaction O.S. of Br changes from 0 ( in `Br_2`) to -1 (in `Br^-`) and +5 (in `BrO_3^-`) .Thus, in this reaction bromine is both oxidised (increases in O.S.) and reduced (decreases in O.S.) - disproportionation reaction.