Which one of the following reactions represent the oxidising properly of `H_(2)O_(2)`?

Options

A. `KMnO_(4)+H_(2)SO_(4)+H_(2)O_(2)toK_(2)SO_(4)+MnSO_(4)+H_(2)O+O_(2)`
B. `K_(3)[Fe(CN)_(6)]+KOH+H_(2)O+O_(2)toK_(4)[Fe(CN)_(6)]+H_(2)O+O_(2)`
C. `PbO_(2)+H_(2)O_(2)toPbO+H_(2)O+O_(2)`
D. None of these

Answer

To determine which reaction represents the oxidizing property of \( H_2O_2 \), we need to analyze the oxidation states of the elements involved in each reaction. An oxidizing agent is a substance that gains electrons (is reduced) and causes another substance to be oxidized (lose electrons).

### Step-by-Step Solution:

1. **Understand the Concept of Oxidizing Agent**:
- An oxidizing agent is a substance that can accept electrons and, in the process, undergo a reduction in its own oxidation state.
- For \( H_2O_2 \) (hydrogen peroxide), we need to check if it is acting as an oxidizing agent by looking for a reaction where its oxidation state decreases.

2. **Analyze Each Reaction**:
- **Option A**: \( KMnO_4 + H_2O_2 \rightarrow MnSO_4 + H_2O \)
- Oxidation state of Mn in \( KMnO_4 \) is +7 and in \( MnSO_4 \) it is +2. This indicates that Mn is reduced (gains electrons).
- The oxidation state of oxygen in \( H_2O_2 \) remains -1, indicating it is acting as a reducing agent here. Thus, this option does not represent the oxidizing property of \( H_2O_2 \).

- **Option B**: \( K_3Fe(CN)_6 + H_2O_2 \rightarrow K_4Fe(CN)_6 + H_2O \)
- The oxidation state of Fe in \( K_3Fe(CN)_6 \) is +3 and in \( K_4Fe(CN)_6 \) it is +2. Again, Fe is reduced.
- The oxidation state of oxygen in \( H_2O_2 \) remains -1, indicating it is acting as a reducing agent here as well. Thus, this option does not represent the oxidizing property of \( H_2O_2 \).

- **Option C**: \( PbO_2 + H_2O_2 \rightarrow PbO + H_2O \)
- The oxidation state of Pb in \( PbO_2 \) is +4 and in \( PbO \) it is +2. Pb is reduced.
- The oxidation state of oxygen in \( H_2O_2 \) remains -1, indicating it is acting as a reducing agent in this case too. Thus, this option does not represent the oxidizing property of \( H_2O_2 \).

3. **Conclusion**:
- After analyzing all the options, none of the reactions show \( H_2O_2 \) acting as an oxidizing agent. Therefore, the correct answer is:
- **Option D**: None of the above.