In the reaction Bromine
`3Br_2 + 6 OH^(-) rarr 5 Br ^(-) + BrO_3^(-) + 3H_2O`

Options

A. is reduced
B. is oxidized
C. disproportionates
D. disintegrates

Answer

To analyze the given reaction and determine the change in the oxidation state of bromine, let's go through the solution step by step.

### Step 1: Identify the Reactants and Products
The reaction provided is:
\[ 3Br_2 + 6OH^- \rightarrow 5Br^- + BrO_3^- + 3H_2O \]

### Step 2: Determine the Oxidation States
- **For \(Br_2\)**: The oxidation state of bromine in \(Br_2\) is 0 (since it is in its elemental form).
- **For \(Br^-\)**: The oxidation state of bromine in \(Br^-\) is -1 (the charge of the ion).
- **For \(BrO_3^-\)**: To find the oxidation state of bromine in \(BrO_3^-\):
- Let the oxidation state of bromine be \(x\).
- The total charge of the ion is -1.
- The three oxygen atoms contribute -6 (since each oxygen has an oxidation state of -2).
- Thus, the equation is:
\[ x + 3(-2) = -1 \]
\[ x - 6 = -1 \]
\[ x = +5 \]
Therefore, the oxidation state of bromine in \(BrO_3^-\) is +5.

### Step 3: Analyze the Changes in Oxidation States
- Bromine changes from:
- 0 in \(Br_2\) to -1 in \(Br^-\) (Reduction)
- 0 in \(Br_2\) to +5 in \(BrO_3^-\) (Oxidation)

### Step 4: Identify the Type of Reaction
Since bromine undergoes both reduction (from 0 to -1) and oxidation (from 0 to +5), this is a disproportionation reaction. In a disproportionation reaction, a single substance is both oxidized and reduced.

### Step 5: Evaluate the Options
1. **Reduce**: Incorrect, as bromine is not only reduced.
2. **Oxidize**: Incorrect, as bromine is not only oxidized.
3. **Disproportionate**: Correct, as bromine undergoes both oxidation and reduction.
4. **Disintegrate**: Incorrect, as there is no breaking down into smaller particles.

### Conclusion
The correct answer is that bromine **disproportionates** in the reaction.

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