Statement-1. The boiling point of `NH_(3) ` lies between that of `SbH_(3) and BiH_(3)`
Statement -2. `PH_(3)` has much lower boiling than `NH_(3)` but it increases from `PH_(3) ` to ` AsH_(3)` to `SbH_(3)` to` BiH_(3)` due to increase in van dar Waals forces

Options

A. Statement-1 is Ture , Statement-2 is Ture , Statement-2 is a correct explanation for Statement-1.
B. Statement-1 is Ture , Statement-2 is Ture , Statement-2 is not a correct explanation for Statement-1.
C. Statement-1 is True , Statement-2 is False .
D. Statement-1 is False, Statement-2 is True.

Explanation

To analyze the given statements, we can break down the reasoning behind the boiling points of the compounds mentioned.

### Step-by-Step Solution:

1. **Understanding Boiling Points**:
- Boiling points of substances are influenced by the types of intermolecular forces present. For example, hydrogen bonding, van der Waals forces (London dispersion forces), and dipole-dipole interactions play significant roles.

2. **Boiling Points of NH3, SbH3, and BiH3**:
- Ammonia (NH3) exhibits strong hydrogen bonding due to the presence of nitrogen, which is highly electronegative. This results in a relatively high boiling point.
- On the other hand, antimony hydride (SbH3) and bismuth hydride (BiH3) primarily experience van der Waals forces, which are weaker than hydrogen bonds. Therefore, their boiling points are expected to be lower than that of NH3.

3. **Comparing Boiling Points**:
- The boiling point of NH3 is higher than both SbH3 and BiH3 due to hydrogen bonding. Thus, the statement that the boiling point of NH3 lies between that of SbH3 and BiH3 is incorrect.

4. **Analyzing Statement 2**:
- Phosphine (PH3) has a lower boiling point than NH3 because it lacks hydrogen bonding and only has van der Waals forces.
- The boiling points of the hydrides increase from PH3 to AsH3 to SbH3 to BiH3 due to increasing molecular weights and the corresponding increase in van der Waals forces. This statement is correct.

5. **Conclusion**:
- Statement 1 is false because NH3 has a higher boiling point than both SbH3 and BiH3.
- Statement 2 is true as it accurately describes the trend in boiling points among PH3, AsH3, SbH3, and BiH3.

### Final Answer:
- Statement 1: False
- Statement 2: True

### Correct Option:
- D: Statement 1 is false, Statement 2 is true.