Which oxide does not act as a reducing agent?

Options

A. `NO`
B. `N_(2)O_(4)`
C. `N_(2)O`
D. `N_(2)O_(5)`

Explanation

To determine which oxide does not act as a reducing agent among NO, N2O4, N2O, and N2O5, we can follow these steps:

### Step 1: Understand the Concept of Reducing Agents
A reducing agent is a substance that donates electrons to another substance, causing the other substance to be reduced while itself gets oxidized. Therefore, reducing agents typically have lower oxidation states and can be oxidized to a higher oxidation state.

### Step 2: Analyze the Oxidation States
Let's look at the oxidation states of nitrogen in each of the given oxides:
- **NO**: Nitrogen has an oxidation state of +2.
- **N2O4**: Nitrogen has an oxidation state of +4.
- **N2O**: Nitrogen has an oxidation state of +1.
- **N2O5**: Nitrogen has an oxidation state of +5.

### Step 3: Identify Oxidizing and Reducing Agents
- **NO**: Can be oxidized to NO2, thus can act as a reducing agent.
- **N2O4**: Can be reduced to NO, thus can act as a reducing agent.
- **N2O**: Can be oxidized to N2O4, thus can act as a reducing agent.
- **N2O5**: Has nitrogen in the highest oxidation state of +5 and cannot be oxidized further. Therefore, it cannot act as a reducing agent and is instead an oxidizing agent.

### Step 4: Conclusion
From the analysis, we conclude that **N2O5** does not act as a reducing agent.

### Final Answer
The oxide that does not act as a reducing agent is **N2O5**.

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