Question

Given below are two statements :
Statement I: The boiling point of hydrides of Group 16 elements follow the order
H₂O > H₂Te > H₂Se > H₂S.
Statement II: On the basis of molecular mass, H₂O is expected to have lower boiling point than the other members of the group but due to the presence of extensive H-bonding in H₂O, it has higher boiling point.
In the light of the above statements, choose the correct answer from the options given below :

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Answer 1

The Correct Option is A

Given below are two statements:

Statement I: The boiling point of hydrides of Group 16 elements follow the order H2O > H2Te > H2Se > H2S.

Statement II: On the basis of molecular mass, H2O is expected to have lower boiling point than the other members of the group but due to the presence of extensive H-bonding in H2O, it has higher boiling point.

In the light of the above statements, choose the correct answer from the options given below:

Explanation:

Statement I:

The boiling points of the hydrides of Group 16 elements generally increase with increasing molecular mass. However, water (H2O) is an exception due to strong hydrogen bonding. The correct order is H2O > H2Te > H2Se > H2S. Therefore, Statement I is correct.

Statement II:

As stated, based on molecular mass alone, H2O should have the lowest boiling point. However, the extensive intermolecular hydrogen bonding in water significantly increases its boiling point, making it higher than the other hydrides in the group. Thus, Statement II is also correct.

Conclusion:

Both Statement I and Statement II are True.