Question

Assertion (A): The boiling point of ethanol is higher than that of methoxymethane.
Reason (R): There is intramolecular hydrogen bonding in ethanol.

• A. Assertion (A) is true, but Reason (R) is false.
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

Hydrogen bonding increases the boiling point of compounds as it requires more energy to break these bonds.

Answer 1

The Correct Option is A

To solve this question, let's analyze the assertion and reason provided.

Assertion (A):
The boiling point of ethanol is higher than that of methoxymethane.

Reason (R):
There is intramolecular hydrogen bonding in ethanol.

1. Boiling Points of Ethanol and Methoxymethane:
Ethanol (C₂H₅OH) has a higher boiling point compared to methoxymethane (CH₃OCH₃). The reason for this difference is primarily due to the presence of hydrogen bonding in ethanol.

2. Hydrogen Bonding in Ethanol:
Ethanol exhibits intermolecular hydrogen bonding between the -OH group of one ethanol molecule and the hydrogen of another ethanol molecule. This strong intermolecular force requires more energy to break, resulting in a higher boiling point for ethanol compared to methoxymethane.

3. Evaluation of Assertion (A):
The assertion that ethanol has a higher boiling point than methoxymethane is correct. Methoxymethane, a simple ether, does not exhibit hydrogen bonding, resulting in a lower boiling point compared to ethanol.

4. Evaluation of Reason (R):
The reason provided is not entirely accurate. While it is true that ethanol has hydrogen bonding, it is intermolecular hydrogen bonding, not intramolecular hydrogen bonding, that influences the boiling point. Therefore, the reason is incorrect.

5. Conclusion:
The assertion is correct, but the reason is incorrect. Ethanol has a higher boiling point due to intermolecular hydrogen bonding, not intramolecular hydrogen bonding.

Final Answer:
The correct option is that the assertion is true, but the reason is false.