Which among th following is mixed anhydride?

Options

A. `N_(2)O_(5)`
B. `NO_(2)`
C. `N_(2)O_(3)`
D. `N_(2)O_(2)`

Answer

To determine which among the given compounds is a mixed anhydride, we need to analyze how each compound reacts with water and what products are formed. A mixed anhydride is defined as a compound that reacts with water to produce two different acidic anhydrides.

Let's evaluate each option step by step:

### Step 1: Analyze N2O5
- **Reaction with Water**:
\[ N_2O_5 + H_2O \rightarrow 2 HNO_3 \]
- **Products**: Nitric acid (HNO3) is formed.
- **Conclusion**: N2O5 does not produce two different acidic anhydrides; it only produces nitric acid. Therefore, it is not a mixed anhydride.

### Step 2: Analyze NO2
- **Reaction with Water**:
\[ NO_2 + H_2O \rightarrow HNO_3 + HNO_2 \]
- **Products**: Nitric acid (HNO3) and nitrous acid (HNO2) are formed.
- **Conclusion**: NO2 produces two different acidic anhydrides, making it a mixed anhydride.

### Step 3: Analyze N2O3
- **Reaction with Water**:
\[ N_2O_3 + H_2O \rightarrow 2 HNO_2 \]
- **Products**: Nitrous acid (HNO2) is formed.
- **Conclusion**: N2O3 does not produce two different acidic anhydrides; it only produces nitrous acid. Therefore, it is not a mixed anhydride.

### Step 4: Analyze N2O2
- **Reaction with Water**:
\[ N_2O_2 + H_2O \rightarrow HNO_2 + N_2O \]
- **Products**: Nitrous acid (HNO2) and nitrogen monoxide (N2O) are formed.
- **Conclusion**: N2O2 does not produce two different acidic anhydrides; it only produces nitrous acid. Therefore, it is not a mixed anhydride.

### Final Conclusion
Among the given options, only NO2 reacts with water to produce two different acidic anhydrides (HNO3 and HNO2). Therefore, the correct answer is:
**Option B: NO2**

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