Question

Ethyl alcohol on distillation with X gives chloroform, X is:
A. A paste of bleaching powder
B. Chlorine
C. Methyl chloride
D. $Ca{(OH)_2}$

Answer 1

Hint: The production of chloroform from ethyl alcohol takes place in three steps where calcium hydroxide and chlorine both are used as one of the reactants which is obtained from reaction of X compound with water.

Complete step by step answer: Bleaching powder is a chemical compound with the formula $CaOC{l_2}$. The bleaching powder is also known as calcium hypochlorite.
Bleaching powder on dissolving in water gives calcium hydroxide and chlorine.
The reaction of bleaching powder with water is shown below.
$CaOC{l_2} + {H_2}O \to Ca{(OH)_2} + C{l_2}$
In this reaction, bleaching powder reacts with water to form calcium hydroxide and chlorine.
The ethyl alcohol reacts with the chlorine of the bleaching powder to form acetaldehyde.
The reaction of ethyl alcohol and chlorine is shown below.
$C{H_3}C{H_2}OH + C{l_2}\xrightarrow{{ - 2HCl}}C{H_3}CHO + 2HCl$
In this reaction, one mole of ethyl alcohol reacts with one mole of chlorine to form one mole of acetaldehyde and two mole of hydrochloric acid.
Acetaldehyde further reacts with more chlorine to give trichloroacetaldehyde.
The reaction of acetaldehyde and chlorine is shown below.
$C{H_3}CHO + 3C{l_2} \to CC{l_3}CHO + 3HCl$
In this reaction, one mole of acetaldehyde reacts with three mole of chlorine to form one mole of trichloroacetaldehyde and three mole of hydrochloric acid.
The trichloroacetaldehyde reacts with calcium hydroxide to form chloroform.
$2CC{l_3}CHO + Ca{(OH)_2} \to 2CHC{l_3} + {(HCOO)_2}Ca$
In this reaction, two mole of trichloroacetaldehyde react with one mole of calcium hydroxide to form two mole of chloroform and one mole of calcium acetate.
Thus, ethyl alcohol on distillation with bleaching powder gives chloroform. X is a paste of bleaching powder.
So, the correct answer is “Option A”.

Note:
 In the whole process of formation of chloroform from ethyl alcohol three reactions take place one is oxidation reaction, second is halogenation reaction and third is hydrolysis reaction.