`Cr_(2)O_(7)^(2-)+Xoverset(H^(o+))rarrCr^(3+)+H_(2)O+ "oxidised product" of X, X` in the above reaction cannot be

Options

A. `C_(2)O_(4)^(2-)`
B. `Fe^(2+)`
C. `SO_(4)^(2-)`
D. `SO_(2-)`

Explanation

To solve the problem, we need to determine which of the given options cannot be oxidized in the reaction involving the dichromate ion \( \text{Cr}_2\text{O}_7^{2-} \) in an acidic medium, producing \( \text{Cr}^{3+} \) and water, along with the oxidized product of \( X \).

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
The reaction is:
\[ \text{Cr}_2\text{O}_7^{2-} + X + 2H^+ \rightarrow 2\text{Cr}^{3+} + H_2O + \text{oxidized product of } X \]
Here, \( X \) is the substance that is being oxidized.

2. **Understand Oxidation**:
Oxidation involves an increase in the oxidation state of an element. We need to check the oxidation states of the elements in \( X \) to determine if they can be oxidized further.

3. **Evaluate Possible Options for \( X \)**:
Let's analyze the common candidates for \( X \) and their oxidation states.

- **Option 1: \( \text{C}_2\text{O}_4^{2-} \) (Oxalate Ion)**:
- The oxidation state of carbon in \( \text{C}_2\text{O}_4^{2-} \) is +3.
- It can be oxidized to a higher oxidation state (e.g., to \( \text{CO}_2 \)).
- **Conclusion**: This can be oxidized.

- **Option 2: \( \text{Fe}^{2+} \)**:
- The oxidation state of iron is +2.
- It can be oxidized to +3 or higher oxidation states.
- **Conclusion**: This can be oxidized.

- **Option 3: \( \text{SO}_4^{2-} \) (Sulfate Ion)**:
- The oxidation state of sulfur in \( \text{SO}_4^{2-} \) is +6.
- This is the highest oxidation state for sulfur; it cannot be oxidized further.
- **Conclusion**: This cannot be oxidized.

- **Option 4: \( \text{SO}_3^{2-} \) (Sulfite Ion)**:
- The oxidation state of sulfur in \( \text{SO}_3^{2-} \) is +4.
- It can be oxidized to +6 (to \( \text{SO}_4^{2-} \)).
- **Conclusion**: This can be oxidized.

4. **Final Conclusion**:
The substance \( X \) that cannot be oxidized in the given reaction is \( \text{SO}_4^{2-} \).

### Answer:
**SO4^(2-) cannot be oxidized further.**