Question

Chloroform can be obtained from:
(A) Methanol
(B) 2-propanol
(C) Methanol
(D) 1-propanol

Answer 1

Hint : Chloroform is an ideal anesthetic. It is a colorless, sweet smelling dense liquid. Chloroform is nonflammable in nature so it can be handled with ethanol. If it is inhaled it can cause shortness of breath and throat irritation. It is a transparent liquid with an ether-like smell. It is found naturally as it is released in air as a result of its formation in chlorination of drinking water or waste water.

Complete Step By Step Answer:
the formation of chloroform takes place by haloform reaction. In this reaction a methyl ketone is reacted with chlorine, bromine or iodine in the presence of hydroxide ions so that a carboxylate ion and a haloform is formed as a product.
To form chloroform, 2- propanol is used and reacted with chlorine so that acetone and hydrochloric acid is formed as a product. Then on further reacting acetone with chlorine the formation of trichloroacetone occurs. The trichloroacetone is then reacted with calcium hydroxide to form chloroform and calcium acetate. The detailed reaction of the above explanation is given below:
Firstly the formation of calcium hydroxide occurs by reacting bleaching powder with water
 $ CaOC{l_2} + {H_2}O \to Ca{(OH)_2} + C{l_2} $
Now 2-propanol is oxidized to form 2-propanone

Now 2-propanone is reacted with chlorine to form trichloroacetone.
     

Now the two molecules of acetone will be reacted with calcium hydroxide to form chloroform and calcium acetate
 $ 2CC{l_3} - CO - C{H_3} + Ca{(OH)_2} \to 2CHC{l_3} + {(C{H_3}COO)_2}Ca $
So the correct option is option ‘b’.

Note :
Chloroform is used in dentistry during root canal procedure. The spectrum of pure chloroform is used for FTIR analysis. It is used as an extraction which is dissolved in fats, greases and oils. It is also used as an indirect food preservative in food packaging materials.