QJEEM24Chf9c9: JEE Main 2024 Chemistry - Class 12 JEEM24Chf9c9 Solution: Given below are two statements: One is labelled as Assertion A…

Assertion A is that alcohols can act as both nucleophiles and electrophiles. This is indeed true.

Alcohols can act as nucleophiles because they have a polar O-H bond; the oxygen atom has a pair of nonbonding electrons that can be donated to electrophiles. For example, in the presence of a strong acid such as hydrochloric acid, the lone pair on the oxygen can attack the positively charged hydrogen atom to form an oxonium ion ($$R-O{H}_2^{+}$$), which then acts as a good leaving group in substitution reactions.

Alcohols can also behave as electrophiles. An example of an alcohol acting as an electrophile is when it reacts with a strong base, such as sodium hydride (NaH), to undergo deprotonation forming an alkoxide ion ($$R-O^{-}$$). The alkoxide ion is a strong nucleophile, but the original alcohol molecule in the presence of a base acts as an electrophile due to the acidity of the hydroxyl hydrogen.

Reason R posits that alcohols react with active metals such as sodium, potassium and aluminum to yield corresponding alkoxides and liberate hydrogen. This is also true. When alcohols react with active metals, the alcohol acts as an acid, donating a hydrogen ion ($$H^{+}$$) to form hydrogen gas ($$H_2$$), while the remaining alkoxide ion ($$R-O^{-}$$) bonds with the metal cation ($$M^{+}$$, where M is an active metal like sodium) to form the alkoxide salt ($$MOR$$).

Now, considering the above explanations, the relationship between Assertion A and Reason R needs to be evaluated:

While both Assertion A and Reason R are indeed true, Reason R is not the correct explanation of Assertion A. Reason R describes a reaction (alcohol with active metal) where the alcohol functions only as an acid (not as a nucleophile or an electrophile). Hence, Reason R does not explain how alcohols can act as both nucleophiles and electrophiles, which is what Assertion A states.

Therefore, the correct answer is:

Option B : Both $$A$$ and $$R$$ are true but $$R$$ is NOT the correct explanation of $$A$$.