Question

An organic compound ${}^{\prime }{X}^{\prime }$ forms an orange-yellow precipitate with $2,4-DNP$ reagent. It does not react with aqueous $\left[Ag\right(N{H}_3{)}_2]N{O}_3.X$ on reduction with $NaB{H}_4$ gives a secondary alcohol and on oxidation with nitric acid yields a dicarboxylic acid containing the same number of carbon atoms. On bromination, $X$ gives a monobromo product. On the basis of these reactions, it can be concluded that $X$:

I. contains aldehydic carbonyl group.
II. contains ketonic carbonyl group
III. contains ester carbonyl group
IV. does not contain $C=C$ bonds.

• A. I only
• B. III and IV
• C. III only
• D. II and IV

Answer 1

The correct option is D II and IV

According to given passage $2,4-DNP$ gives test for both aldehydes and ketones. But $\left[Ag\right(N{H}_3{)}_2]N{O}_3$ ammonical silver nitrate test given only by aldehydes. So, $X$ is ketone.

Only ketones can give secondary alcohols on reaction with $NaB{H}_4$ because aldehydes gives primary alcohols.

And the ketone has saturated alkyl chain because unsaturated alkyl chains cannot form monobromo products.

Hence, $X$ contains ketonic carbonyl group and does not contain $C=C$ bonds.