In alkaline medium, `ClO_(2)` oxidises `H_(2)O_(2) "to" O_(2)` and is itself reduced to `Cl^(ө)`. How many moles of `H_(2)O_(2)` are oxidised by `1 "mol of " ClO_(2)` ?

Options

A. 1
B. `3//2`
C. `5//2`
D. `7//2`

Explanation

To solve the problem, we need to determine how many moles of hydrogen peroxide (H₂O₂) are oxidized by one mole of chlorine dioxide (ClO₂) in an alkaline medium.

### Step-by-Step Solution:

1. **Write the balanced chemical equation**:
In alkaline medium, the reaction can be represented as:
\[ 2 \text{ClO}_2 + 5 \text{H}_2\text{O} + 2 \text{OH}^- \rightarrow 2 \text{Cl}^- + 5 \text{O}_2 + 6 \text{H}_2\text{O} \]
This equation shows that 2 moles of ClO₂ react with 5 moles of H₂O₂.

2. **Identify the stoichiometric relationship**:
From the balanced equation, we can see that:
- 2 moles of ClO₂ oxidize 5 moles of H₂O₂.

3. **Calculate the moles of H₂O₂ oxidized by 1 mole of ClO₂**:
To find out how many moles of H₂O₂ are oxidized by 1 mole of ClO₂, we set up a ratio based on the stoichiometry from the balanced equation:
\[ \text{If } 2 \text{ moles of ClO}_2 \text{ oxidize } 5 \text{ moles of H}_2\text{O}_2, \text{ then } 1 \text{ mole of ClO}_2 \text{ will oxidize } \frac{5}{2} \text{ moles of H}_2\text{O}_2. \]

4. **Final Answer**:
Therefore, 1 mole of ClO₂ oxidizes \( \frac{5}{2} \) moles of H₂O₂.

### Conclusion:
The final answer is that 1 mole of ClO₂ oxidizes \( \frac{5}{2} \) moles of H₂O₂.