What is the action of phenylhydrazine on formaldehyde ?

Explanation

To determine the action of phenylhydrazine on formaldehyde, we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are formaldehyde (HCHO) and phenylhydrazine (C6H5NH-NH2).

### Step 2: Understand the Reaction Mechanism
Phenylhydrazine reacts with formaldehyde to form a hydrazone. The reaction involves the nucleophilic attack of the nitrogen atom in phenylhydrazine on the carbonyl carbon of formaldehyde.

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