Question

Aldehydes and ketones can be distinguished by:

• A. Tollens reagent
• B. 2, 4 DNP test
• C. Molisch test
• D. Mullikans test

Answer 1

Answer: (A)

Define all terms
(a) Tollens reagent: It is ammoniacal silver nitrate. The aldehydes reduce it to silver and ketones shows no reaction. It is used to distinguish between aldehydes and ketones.
(b) 2,4 DNP test: Both aldehydes and ketones form orange ppt. with 2,4 DNP.
(c) Molisch test: $1\%$ alcoholic solution of $\alpha$ naphthol is Molisch reagent. It is used to test carbohydrates in food.
(d) Mullikans test: It is done to determine charge on electron $\therefore$ choice (a) Tollens reagent is used to distinguish between aldehyde and ketones.