Which ion cannot be oxidizes by ozone?

Options

A. `l^(-)`
B. `AsO_(3)^(3-)`
C. `[Fe(CN)_(6)]^(3-)`
D. `MnO_(4)^(2-)`

Explanation

To determine which ion cannot be oxidized by ozone, we need to analyze the oxidation states of the ions provided in the options. Ozone (O₃) acts as a strong oxidizing agent due to the presence of reactive oxygen species that can oxidize other substances.

### Step-by-Step Solution:

1. **Understanding Ozone's Oxidizing Properties**:
- Ozone decomposes to form reactive oxygen species that can oxidize other ions.

2. **Analyzing Each Ion**:
- **Option A: Iodide Ion (I⁻)**:
- The oxidation state of iodine in iodide is -1.
- The maximum oxidation state of iodine is +7.
- Therefore, iodide can be oxidized by ozone to higher oxidation states (e.g., I⁺, I₃⁻, I₂, etc.).

- **Option B: Arsenite Ion (AsO₃³⁻)**:
- The oxidation state of arsenic in arsenite is +3.
- The maximum oxidation state of arsenic is +5.
- Thus, arsenite can also be oxidized by ozone to a higher oxidation state.

- **Option C: Ferricyanide Ion (Fe(CN)₆³⁻)**:
- Let the oxidation state of iron be X.
- The equation is: X - 6 = -3 (since CN⁻ has a charge of -1 and there are 6 CN⁻).
- Solving gives X = +3.
- The maximum oxidation state of iron is +3, meaning it is already in its highest oxidation state and cannot be oxidized further by ozone.

- **Option D: Manganate Ion (MnO₄²⁻)**:
- Let the oxidation state of manganese be X.
- The equation is: X - 4(2) = -2, which simplifies to X - 8 = -2, giving X = +6.
- The maximum oxidation state of manganese is +7.
- Therefore, the manganate ion can be oxidized by ozone to +7.

3. **Conclusion**:
- The ion that cannot be oxidized by ozone is **Option C: Ferricyanide Ion (Fe(CN)₆³⁻)**, as it is already at its maximum oxidation state.

### Final Answer:
**Option C: Ferricyanide Ion (Fe(CN)₆³⁻)** cannot be oxidized by ozone.