What is the trend of boiling points of hydrides of N, O and F ?

Options

A. Due to lower molecular masses `NH_(3), H_(2)O` and HF have lower boiling points than those of the subsequent group member hydrides.
B. Due to higher electronegativity of N, O and F, `NH_(3), H_(2)O` and HF show hydrogen bonding and hence higher boiling points than the hydrides of their subsequent group members.
C. There is no regular trend in the boiling points of hydrides.
D. Due to higher oxidation states of N, O and F, the boiling points of `NH_(3), H_(2)O` and HF are higher than the hydrides of their subsequent group members.

Explanation

To determine the trend of boiling points of the hydrides of nitrogen (N), oxygen (O), and fluorine (F), we will analyze the hydrides: ammonia (NH₃), water (H₂O), and hydrogen fluoride (HF).

### Step-by-Step Solution:

1. **Identify the Hydrides**:
- The hydride of nitrogen is NH₃ (ammonia).
- The hydride of oxygen is H₂O (water).
- The hydride of fluorine is HF (hydrogen fluoride).

2. **Understand the Role of Electronegativity**:
- Electronegativity affects the strength of hydrogen bonding in these compounds. The more electronegative the atom, the stronger the hydrogen bond it can form with hydrogen.
- The electronegativity order is: F > O > N.

3. **Analyze Hydrogen Bonding**:
- HF has the highest electronegativity and thus forms the strongest hydrogen bonds.
- H₂O, with the next highest electronegativity, forms strong hydrogen bonds as well, but not as strong as HF.
- NH₃ has the lowest electronegativity among the three and thus has weaker hydrogen bonds compared to H₂O and HF.

4. **Assign Boiling Points Based on Hydrogen Bonding**:
- Since boiling points are directly related to the strength of hydrogen bonding, we can assign the boiling points as follows:
- HF has the highest boiling point due to strong hydrogen bonding.
- H₂O has a lower boiling point than HF but higher than NH₃ due to its strong hydrogen bonding.
- NH₃ has the lowest boiling point because it has weaker hydrogen bonds compared to H₂O and HF.

5. **Conclusion on the Trend**:
- The trend of boiling points for the hydrides is:
- HF > H₂O > NH₃

### Final Answer:
The trend of boiling points of the hydrides of N, O, and F is: **HF > H₂O > NH₃**.