Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. Which one of the following is obtained when acetone is treated with bleaching powder?

AMUAMU 2001

Solution:

When acetone is treated with bleaching powder, then chloroform is formed.
Bleaching powder $\left( CaOCl _{2}\right)$ supplies the necessary chlorine and slaked lime (calcium hydroxide) for the reaction.
$\underset {\text{bleaching powder}}{CaOCl _{2}} + H _{2} O \longrightarrow \underset{\text{slaked lime}}{Ca ( OH )_{2}+ Cl _{2}}$
Chlorine so obtained acts as a chlorinating agent. It reacts with acetone and gives trichloroacetone which formed chloroform on hydrolysis.
$\underset{\text{acetone}}{CH _{3} COCH _{3}}+3 Cl _{2} \longrightarrow \underset{\text{trichloroacetone}}{C \cdot Cl _{3} \cdot COCH _{3}}+3 HCl$
$Ca ( OH )_{2}+2 CCl _{3} COCH _{3} \longrightarrow \underset{\text { chloroform }}{2 CHCl _{3}} +\underset{\text{calcium acetate}}{\left( CH _{3} COO \right)_{2} Ca}$
This is the laboratory method of chloroform preparation.
Ethyl alcohol also gives chloroform with bleaching powder. In this reaction bleaching powder functions as oxidising, chlorinating and hydrolysing agent.