Which of the following hydrides of group 16 elements has the highest boiling point ?

Options

A. `H_(2)O`
B. `H_(2)S`
C. `H_(2)Se`
D. `H_(2)Te`

Answer

To determine which hydride of group 16 elements has the highest boiling point, we will analyze the boiling points of the given hydrides: H₂O (water), H₂S (hydrogen sulfide), H₂Se (hydrogen selenide), and H₂Te (hydrogen telluride).

### Step-by-Step Solution:

1. **List the Hydrides**:
- H₂O (water)
- H₂S (hydrogen sulfide)
- H₂Se (hydrogen selenide)
- H₂Te (hydrogen telluride)

2. **Consider Molecular Weights**:
- The molecular weights of the hydrides generally increase down the group.
- H₂O: 18 g/mol
- H₂S: 34 g/mol
- H₂Se: 80 g/mol
- H₂Te: 130 g/mol

3. **Analyze Boiling Points**:
- Typically, boiling points increase with molecular weight due to increased van der Waals forces.
- However, water (H₂O) is an exception due to the presence of hydrogen bonding.

4. **Identify Hydrogen Bonding**:
- Water exhibits strong hydrogen bonding because oxygen is highly electronegative and has lone pairs that can interact with hydrogen atoms.
- This leads to a significantly higher boiling point compared to other hydrides in the group.

5. **Compare Boiling Points**:
- H₂S has a boiling point of -60 °C.
- H₂Se has a boiling point of -41 °C.
- H₂Te has a boiling point of -2 °C.
- H₂O has a boiling point of 100 °C.

6. **Conclusion**:
- Despite having a lower molecular weight, water (H₂O) has the highest boiling point among the group 16 hydrides due to strong hydrogen bonding.

### Final Answer:
The hydride of group 16 elements with the highest boiling point is **H₂O (water)**.