`NO_2` is a mixed anhydride. (T/F).

Answer

To determine whether the statement "NO₂ is a mixed anhydride" is true or false, we can follow these steps:

### Step 1: Define Anhydride
An anhydride is a compound that is formed by the removal of a water molecule from an acid. It can be derived from one acid (simple anhydride) or from two different acids (mixed anhydride).

**Hint:** Recall the definition of anhydrides and the process of their formation.

### Step 2: Identify the Formation of NO₂
NO₂ (nitrogen dioxide) can be formed from the combination of two different acids: nitric acid (HNO₃) and nitrous acid (HNO₂). When these two acids react, they release a water molecule.

**Hint:** Think about the acids involved and how they can combine to form NO₂.

### Step 3: Write the Reaction
The reaction can be represented as follows:
\[ HNO_3 + HNO_2 \rightarrow NO_2 + H_2O \]
In this reaction, we can see that two different acids (HNO₃ and HNO₂) combine, and a water molecule is released, resulting in the formation of nitrogen dioxide (NO₂).

**Hint:** Consider balancing the equation to confirm the conservation of atoms.

### Step 4: Analyze the Result
Since NO₂ is formed from the combination of two different acids and involves the removal of a water molecule, it fits the definition of a mixed anhydride.

**Hint:** Reflect on the characteristics of mixed anhydrides and how NO₂ aligns with them.

### Step 5: Conclusion
Based on the above analysis, we conclude that the statement "NO₂ is a mixed anhydride" is true.

**Final Answer:** True

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