`Br_2` undergoes disproportionation reaction in basic medium to give `Br^(ɵ)` ion and `BrO_3^(ɵ)` (bromate) ion in reduction and oxidation reaction.

Explanation

To solve the problem of the disproportionation reaction of \( Br_2 \) in a basic medium, we will break it down into a series of steps.

### Step 1: Write the Half-Reactions
The first step is to identify the half-reactions for the reduction and oxidation processes.

1. **Reduction Half-Reaction**:
\[
Br_2 + 2e^- \rightarrow 2Br^-
...