Q. $C_{2} H_{5} C H O$ and $(C H_{3})_{2} CO$ can be distinguished by testing with

2880 187 ManipalManipal 2008Aldehydes Ketones and Carboxylic Acids Report Error

A

phenyl hydrazine

B

hydroxyl amine

C

Fehling solution

D

sodium bisulphite

Solution:

Fehling solution is only reduced by aldehydes but not by ketones, therefore it is used to distinguish between aldehyde $(C_{2} H_{5} C H O)$ and ketone $(C H_{3})_{2} CO .$
$C_{2} H_{5} C H O + Fehling solution C u (O H)_{2} ⟶ C_{2} H_{5} COO H + red ppt C u_{2} O + H_{2} O$
$(C H_{3})_{2} C = Fehling solution O + C u (O H)_{2} ⟶$ No reaction