Question

Identify the N-substituted derivative of carbonyl compounds that are coloured compounds and are useful in the identification of aldehydes and ketones.

(a) Hydrazone

(b) Phenylhydrazone

(c) 2,4-Dinitrophenylhydrazone

(d) Semicarbazone

This question was posed to me in an internship interview.

I'm obligated to ask this question of Aldehydes and Ketones Chemical Reactions in portion Aldehydes, Ketones and Carboxylic Acids of Chemistry – Class 12

Answer 1

Right answer is (c) 2,4-Dinitrophenylhydrazone

Best explanation: 2,4-DNP derivatives are formed from the reaction between aldehydes or ketones and 2,4-Dinitrohydrazine. These products may be yellow, orange or ed coloured and help in characterisation of aldehydes and ketones.