Which of the following has the highest boiling point?

Options

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

Explanation

To determine which of the given compounds has the highest boiling point, we will analyze the boiling points of arsenic hydride (AsH3), antimony hydride (SbH3), phosphorus hydride (PH3), and nitrogen hydride (NH3).

### Step-by-Step Solution:

1. **Understanding Boiling Point**:
- The boiling point is the temperature at which a liquid turns into vapor. It is influenced by the type of intermolecular forces present in the substance.

2. **Identifying the Compounds**:
- The compounds given are:
- Arsenic hydride (AsH3)
- Antimony hydride (SbH3)
- Phosphorus hydride (PH3)
- Nitrogen hydride (NH3)

3. **Examining Intermolecular Forces**:
- The primary intermolecular forces that affect boiling points include hydrogen bonding and Van der Waals forces.
- NH3 exhibits strong hydrogen bonding due to the presence of a highly electronegative nitrogen atom bonded to hydrogen.

4. **Comparing Boiling Points**:
- **NH3 (Nitrogen Hydride)**: Has strong hydrogen bonding, which results in a higher boiling point compared to the other hydrides. Its boiling point is approximately 238.5 K.
- **PH3 (Phosphorus Hydride)**: Has weaker Van der Waals forces compared to NH3, resulting in a lower boiling point.
- **AsH3 (Arsenic Hydride)**: Similar to PH3, it has weaker Van der Waals forces.
- **SbH3 (Antimony Hydride)**: As we move down the group in the nitrogen family, the molecular size increases, leading to stronger Van der Waals forces. Therefore, SbH3 has a higher boiling point than both AsH3 and PH3.

5. **Final Comparison**:
- The boiling points are as follows:
- NH3: 238.5 K
- PH3: Lower than NH3
- AsH3: Lower than NH3
- SbH3: 254.6 K (highest among them)
- Thus, SbH3 has the highest boiling point due to its higher molecular weight and stronger Van der Waals forces.

6. **Conclusion**:
- The compound with the highest boiling point among the given options is **Antimony Hydride (SbH3)**.