Question

Draw the structure of 2, 4 - dinitrophenylhydrazone of acetaldehyde.

Hint:

2,4-DNP test is a general test for the presence of a carbonyl group (\(C=O\)).

Answer 1

Step 1: Understanding the Concept:
Aldehydes react with 2,4-dinitrophenylhydrazine (2,4-DNP) to form crystalline solids called 2,4-dinitrophenylhydrazones.
Step 3: Detailed Explanation:
The reaction involves the loss of a water molecule from the carbonyl oxygen of the aldehyde and the two hydrogen atoms of the primary amino group of 2,4-DNP.
The structure consists of an ethylidene group linked to the nitrogen of the hydrazine moiety.
Chemical Formula:
\[ CH_3-CH=N-NH-C_6H_3(NO_2)_2 \]
The benzene ring has nitro groups at the 2 and 4 positions relative to the point of attachment of the nitrogen atom.
Step 4: Final Answer:
The structure is the condensation product of acetaldehyde and 2,4-DNP.