Question

Given below are two statements:
One is labelled as Assertion A and the other is labelled as Reason R: 
Assertion A: Alcohols react both as nucleophiles and electrophiles. 
Reason R: Alcohols react with active metals such as sodium, potassium and aluminum to yield corresponding alkoxides and liberate hydrogen. 
In the light of the above statements, choose the correct answer from the options given below:

• A. A is false but R is true.
• B. A is true but R is false.
• C. Both A and R are true and R is the correct explanation of A.
• D. Both A and R are true but R is NOT the correct explanation of A.

Answer 1

The Correct Option is D

To solve this question, we need to evaluate the correctness of the given assertion and reason and understand their relationship.

1. Understanding Assertion A: "Alcohols react both as nucleophiles and electrophiles."
   • An alcohol molecule typically contains a hydroxyl group \((\text{-OH})\). The presence of the lone pair on the oxygen atom makes alcohols nucleophilic, meaning they can donate a pair of electrons to form new bonds.
   • The hydroxyl hydrogen can be lost as a proton \((\text{H}^{+})\), leaving behind an alkoxide ion. This ability to accept electrons and donate a proton also makes them behave like electrophiles.
   • Therefore, Assertion A is true.
2. Understanding Reason R: "Alcohols react with active metals such as sodium, potassium, and aluminum to yield corresponding alkoxides and liberate hydrogen."
   • When alcohols react with active metals, the hydrogen in the hydroxyl group is replaced by the metal, forming an alkoxide and releasing hydrogen gas. This is a common reaction for alcohols with reactive metals.
   • This statement is true as it accurately describes the behaviour of alcohols with active metals.
3. Evaluating the Reason:
   • Although both statements are true, Reason R explains a specific reaction of alcohols with metals, which demonstrates their acidic behavior (electrophilic property) rather than their overall ability to act both as nucleophiles and electrophiles.
   • Thus, while R is a true statement, it does not fully explain why alcohols act both as nucleophiles and electrophiles. So R is not the correct explanation of A.
4. Conclusion: The correct answer is "Both A and R are true but R is NOT the correct explanation of A."

Answer 2

As per NCERT, Assertion (A) and Reason (R) is correct but Reason (R) is not the correct explanation.