In the reaction $3 \mathrm{Br}_{2}+6 \mathrm{CO}_{3}^{2-}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow 5…
In the reaction
$3 \mathrm{Br}_{2}+6 \mathrm{CO}_{3}^{2-}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow 5 \mathrm{Br}^{-}+\mathrm{BrO}_{3}^{-}+6 \mathrm{HCO}_{3}^{-}$
Bromine is oxidised and carbonate is reduced.
Bromine is reduced and water is oxidised.
Bromine is neither reduced nor oxidised.
Bromine is both reduced and oxidised.
Solution
$\begin{aligned}
3 \mathrm{Br}_{2}+6 \mathrm{CO}_{3}^{2-}+3 \mathrm{H}_{2} \mathrm{O} & \rightarrow \\
5 \mathrm{Br}^{-} &+\mathrm{BrO}_{3}^{-}+6 \mathrm{HCO}_{3}^{-}
\end{aligned}$
O.N. of $\mathrm{Br}_{2}$ changes from 0 to -1 and +5 , hence it is reduced as well as oxidised.