Which of the following is not correct?

Options

A. Hydrolysis of `NCI_(3)` gives `NH_(3)` and `HOCI`
B. `NH_(3)` is less stable than `PH_(3)`
C. `NH_(3)` is a weak reducing agent compared to `PH_(3)`
D. Nitric oxide in solid state exhibits dia magnetic property Oxyacids

Answer

To solve the question "Which of the following is not correct?" regarding the properties of nitrogen and phosphorus compounds, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze Statement 1: Hydrolysis of NCl3 gives ammonia and HCl.**
- When nitrogen trichloride (NCl3) is hydrolyzed, it reacts with water (H2O) to produce ammonia (NH3) and hydrochloric acid (HCl).
- The balanced chemical equation for this reaction is:
\[ NCl_3 + 3H_2O \rightarrow NH_3 + 3HCl \]
- This statement is **correct**.

2. **Analyze Statement 2: Ammonia is less stable than PH3.**
- Ammonia (NH3) has shorter N-H bonds compared to the P-H bonds in phosphine (PH3) due to the smaller size of nitrogen compared to phosphorus.
- Shorter bond lengths generally indicate stronger bonds, which means ammonia is more stable than phosphine.
- Therefore, this statement is **incorrect**.

3. **Analyze Statement 3: Ammonia is a weaker reducing agent compared to phosphine.**
- The bond strength of NH is greater than that of PH, meaning NH bonds do not break as easily as PH bonds.
- Since stronger bonds are less likely to donate electrons, ammonia (NH3) is indeed a weaker reducing agent than phosphine (PH3).
- Thus, this statement is **correct**.

4. **Analyze Statement 4: Nitric oxide in solid state exhibits diamagnetic property.**
- In the solid state, nitric oxide (NO) forms dimers (N2O2) where the unpaired electron in NO pairs up, resulting in a diamagnetic property.
- Therefore, this statement is **correct**.

### Conclusion:
Based on the analysis, the statement that is not correct is **Statement 2: Ammonia is less stable than PH3**.

### Final Answer:
The incorrect statement is **Statement 2**.

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