The correct order of boiling point of the hybrides of nitrogen family of

Options

A. `NH_(3) gt PH_(3) gt AsH_(3) gt SbH_(3)`
B. `PH_(3)lt AsH_(3) lt NH_(3) lt SbH_(3) `
C. `NH_(3) lt PH_(3) lt SbH_(3) lt AsH_(3) `
D. `NH_(3) lt PH_(3) lt AsH_(3) lt SbH_(3)`

Explanation

To determine the correct order of boiling points of the hydrides of the nitrogen family (NH3, PH3, AsH3, and SbH3), we can analyze the factors that influence boiling points, such as molecular weight, intermolecular forces, and the structure of the molecules.

### Step-by-Step Solution:

1. **Identify the Hydrides**: The hydrides of the nitrogen family include:
- NH3 (Ammonia)
- PH3 (Phosphine)
- AsH3 (Arsine)
- SbH3 (Stibine)

2. **Consider Molecular Weight**: As we move down the group from nitrogen to antimony, the molecular weight of the hydrides increases:
- NH3: 17 g/mol
- PH3: 34 g/mol
- AsH3: 77 g/mol
- SbH3: 124 g/mol

3. **Intermolecular Forces**: The boiling point of a substance is influenced by the type and strength of intermolecular forces present:
- NH3 exhibits hydrogen bonding due to the high electronegativity of nitrogen, which significantly increases its boiling point.
- PH3, AsH3, and SbH3 primarily exhibit van der Waals forces, which are weaker than hydrogen bonds.

4. **Analyze the Boiling Points**:
- NH3 has a high boiling point due to hydrogen bonding.
- PH3 has a lower boiling point than NH3 but higher than AsH3 and SbH3 due to its larger molecular size and weaker intermolecular forces.
- AsH3 has a boiling point lower than PH3 but higher than SbH3.
- SbH3 has the lowest boiling point among these hydrides.

5. **Conclusion**: Based on the analysis of molecular weight and intermolecular forces, the correct order of boiling points from highest to lowest is:
- NH3 > PH3 > AsH3 > SbH3

### Final Order:
- **Correct Order**: NH3 > PH3 > AsH3 > SbH3