The oxide which cannot act as reducing agent is

Options

A. `SO_(2)`
B. `NO_(2)`
C. `CO_(2)`
D. `ClO_(2)`

Explanation

To determine which oxide cannot act as a reducing agent, let's analyze the oxidation states and properties of common oxides.

### Step-by-Step Solution:

1. **Understanding Reducing Agents**: A reducing agent is a substance that donates electrons in a chemical reaction and gets oxidized itself. For an oxide to act as a reducing agent, it must be able to increase its oxidation state.

2. **Identify the Oxides**: We need to consider common oxides of elements from the carbon family (Group 14), particularly carbon oxides like CO and CO2.

3. **Oxidation States**:
- **Carbon Monoxide (CO)**: In CO, carbon has an oxidation state of +2. It can donate electrons and can be oxidized to CO2, thus acting as a reducing agent.
- **Carbon Dioxide (CO2)**: In CO2, carbon has an oxidation state of +4. This is the highest oxidation state for carbon.

4. **Vacant D Orbitals**: Carbon does not have vacant d orbitals, which means it cannot expand its oxidation state beyond +4. Therefore, it cannot be further oxidized.

5. **Conclusion**: Since CO2 is already in its highest oxidation state (+4), it cannot act as a reducing agent. Thus, the oxide that cannot act as a reducing agent is CO2.

### Final Answer:
The oxide which cannot act as a reducing agent is **CO2**.

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