Which of the following statement are correct regarding this equation
`Br_(2) to BrCO_(3)^(-) + Br^(-)` ?

Options

A. Bromine is oxidised
B. Bromine is reduced
C. It is an example of disproportionation reaction
D. Bromine is neither oxidised nor reduced

Answer

To analyze the given reaction \( \text{Br}_2 \rightarrow \text{BrCO}_3^{-} + \text{Br}^{-} \) and determine which statements are correct, we can follow these steps:

### Step 1: Determine the oxidation states of bromine in the reactants and products.
- In the reactant \( \text{Br}_2 \), bromine is in its elemental form, so the oxidation state is 0.
- In the product \( \text{BrCO}_3^{-} \), we need to find the oxidation state of bromine. The overall charge of the ion is -1, and we can assume that the oxidation state of carbon is +4 (since it is in a carbonate ion, CO3). Therefore, we can set up the equation:
\[ x + 4(-2) = -1 \implies x - 8 = -1 \implies x = +1 \]
Thus, the oxidation state of bromine in \( \text{BrCO}_3^{-} \) is +1.
- In the product \( \text{Br}^{-} \), the oxidation state of bromine is -1.

### Step 2: Identify oxidation and reduction processes.
- Oxidation is defined as the increase in oxidation state. Here, bromine goes from 0 in \( \text{Br}_2 \) to +1 in \( \text{BrCO}_3^{-} \). Therefore, bromine is oxidized.
- Reduction is defined as the decrease in oxidation state. Here, bromine goes from 0 in \( \text{Br}_2 \) to -1 in \( \text{Br}^{-} \). Therefore, bromine is reduced.

### Step 3: Determine if the reaction is a disproportionation reaction.
- A disproportionation reaction occurs when the same element is both oxidized and reduced in the same reaction. Since bromine is being oxidized to \( \text{BrCO}_3^{-} \) and reduced to \( \text{Br}^{-} \), this reaction qualifies as a disproportionation reaction.

### Conclusion:
Based on the analysis:
1. Bromine is oxidized (correct).
2. Bromine is reduced (correct).
3. The reaction is a disproportionation reaction (correct).
4. Any statement claiming otherwise would be incorrect.

### Final Answer:
- Statements 1, 2, and 3 are correct.
- Statement 4 is incorrect.