Nucleophiles, such as ammonia and its derivatives \(H_2N-Z\) add to the carbonyl group of aldehydes and ketones. The reaction is reversible and catalyzed by acid. The equilibrium favours the product formation due to rapid dehydration of the intermediate to form \(-C=N-Z\), where, \(Z =\) Alkyl, aryl, \(OH\), \(NH_2\), \(C_6H_5NH\), \(NHCONH_2\), etc.

What happens when acetone reacts with phenylhydrazine?

Acetone phenyl hydrazone 

The correct answer is option 2. Acetone phenyl hydrazone.

When acetone reacts with phenylhydrazine, the product formed is acetone phenylhydrazone.

The carbonyl group of acetone (\( \text{C=O} \)) reacts with phenylhydrazine to form a phenylhydrazone. This reaction involves the nucleophilic attack of the nitrogen in phenylhydrazine on the carbonyl carbon, followed by the elimination of water.

The product of this reaction is acetone phenylhydrazone, characterized by the formation of a \( \text{C=N} \) bond between the acetone and phenylhydrazine. When acetone reacts with phenylhydrazine, the product formed is acetone phenylhydrazone.