Which of the following compound cannot be oxidised by `O_(3)`?

Options

A. Kl
B. `KMnO_(4)`
C. `K_(2)MnO_(4)`
D. `FeSO_(4)`

Answer

To determine which compound cannot be oxidized by Ozone (O3), we need to analyze the oxidation states of the elements in each compound and see if they can be further oxidized by O3.

### Step-by-Step Solution:

1. **Identify the Compounds**: The given compounds are:
- A) KI (Potassium Iodide)
- B) KMnO4 (Potassium Permanganate)
- C) K2MnO4 (Potassium Manganate)
- D) FeSO4 (Ferrous Sulfate)

2. **Analyze KI (Potassium Iodide)**:
- In KI, potassium (K) has an oxidation state of +1 and iodine (I) has an oxidation state of -1.
- When O3 reacts with KI, iodine is oxidized from -1 to 0 (I2), indicating that it loses one electron.
- Therefore, O3 can oxidize KI.

3. **Analyze KMnO4 (Potassium Permanganate)**:
- In KMnO4, potassium (K) is +1, manganese (Mn) is +7, and oxygen (O) is -2.
- The oxidation state of manganese is already at its maximum (+7), and it cannot be oxidized further.
- Therefore, O3 cannot oxidize KMnO4.

4. **Analyze K2MnO4 (Potassium Manganate)**:
- In K2MnO4, potassium (K) is +1, manganese (Mn) is +6, and oxygen (O) is -2.
- The oxidation state of manganese can be increased from +6 to +7 when it reacts with O3, indicating that it can be oxidized.
- Therefore, O3 can oxidize K2MnO4.

5. **Analyze FeSO4 (Ferrous Sulfate)**:
- In FeSO4, iron (Fe) is +2 and sulfate (SO4) is -2.
- When O3 reacts with FeSO4, iron is oxidized from +2 to +3, indicating that it loses one electron.
- Therefore, O3 can oxidize FeSO4.

6. **Conclusion**:
- The only compound that cannot be oxidized by O3 is **KMnO4** (Potassium Permanganate).

### Final Answer:
**B) KMnO4**