Solid `N_2 O_5` exists as `NO_2^(oplus) NO_3^(Ө)` and hence is called nitronium nitrate.
Which of the following statement is correct for the oxides of nitrogen ?

Options

A. Dinitrogen trioxide dissolves in potassium hydroxide forming potassium nitrate.
B. Aqueous solution of nitrogen dioxide behaves both as a reducing agent and as an oxidising agent.
C. `NO_2` is non-planar.
D. Nitrous oxide is fairly soluble in cold water and turns blue litmus red.

Answer

To solve the question regarding the correct statement for the oxides of nitrogen, let's analyze each option step by step.

### Step 1: Analyze Option 1
**Statement:** Dinitrogen trioxide dissolves in potassium hydroxide forming potassium nitrate.

- **Explanation:** Dinitrogen trioxide (N2O3) is an acidic oxide. When it reacts with potassium hydroxide (KOH), it forms potassium nitrite (KNO2) and water, not potassium nitrate (KNO3). Therefore, this statement is incorrect.

### Step 2: Analyze Option 2
**Statement:** Aqueous solution of nitrogen dioxide behaves both as a reducing agent and oxidizing agent.

- **Explanation:** Nitrogen dioxide (NO2) has an oxidation state of +4. It can either increase its oxidation state to +5 (acting as a reducing agent) or decrease its oxidation state to +3 or +2 (acting as an oxidizing agent). Thus, this statement is correct.

### Step 3: Analyze Option 3
**Statement:** NO2 is non-planar.

- **Explanation:** The molecular structure of nitrogen dioxide (NO2) is bent due to the presence of a lone electron on nitrogen and has sp2 hybridization. This results in a planar structure. Therefore, this statement is incorrect.

### Step 4: Analyze Option 4
**Statement:** Nitrous oxide is fairly soluble in cold water and turns blue litmus red.

- **Explanation:** While nitrous oxide (N2O) is indeed fairly soluble in cold water, it is a neutral oxide and does not turn blue litmus paper red. Therefore, this statement is also incorrect.

### Conclusion
After analyzing all options, the correct statement regarding the oxides of nitrogen is:

**Correct Answer:** Option 2 - Aqueous solution of nitrogen dioxide behaves both as a reducing agent and oxidizing agent.

---