Which of the following is called mixed anhydride ?

Options

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

Answer

To determine which of the given compounds is called a mixed anhydride, we will analyze each option and see how they react with water.

### Step 1: Understand the definition of mixed anhydride
A mixed anhydride is a compound that, when it reacts with water, produces a mixture of two different acids.

### Step 2: Analyze the first compound, NO2 (Nitrogen Dioxide)
When NO2 reacts with water, the reaction can be represented as:
\[ \text{NO}_2 + \text{H}_2\text{O} \rightarrow \text{HNO}_3 + \text{HNO}_2 \]
This results in the formation of two different acids: Nitric Acid (HNO3) and Nitrous Acid (HNO2). Therefore, NO2 is a mixed anhydride.

### Step 3: Analyze the second compound, N2O3 (Dinitrogen Trioxide)
When N2O3 reacts with water, the reaction can be represented as:
\[ \text{N}_2\text{O}_3 + \text{H}_2\text{O} \rightarrow 2 \text{HNO}_2 \]
This reaction produces only one type of acid, Nitrous Acid (HNO2). Therefore, N2O3 is not a mixed anhydride.

### Step 4: Analyze the third compound, N2O5 (Dinitrogen Pentoxide)
When N2O5 reacts with water, the reaction can be represented as:
\[ \text{N}_2\text{O}_5 + \text{H}_2\text{O} \rightarrow 2 \text{HNO}_3 \]
This reaction produces only one type of acid, Nitric Acid (HNO3). Therefore, N2O5 is also not a mixed anhydride.

### Conclusion
After analyzing all three compounds, we find that only NO2 produces a mixture of two acids when reacted with water. Thus, the correct answer is:
**NO2 is called a mixed anhydride.**

---