Properties and Methods Of Preparation of Chloroform (Trichloromethane) CHCl₃

(i) Distillation of chloral hydrate and NaOH -  solution gives chloroform by distillation of chloral hydrate and NaOH solution.

When ethanol, acetone or acetaldehyde is heated with bleaching powder and water, CHCl₃ is obtained. Here the bases and halogens formed from bleaching powder and H₂O take part in the reaction.

Main Properties - Chloroform is colourless, tastefully odour, volatile and non-flammable liquid.

It is heavier than water and insoluble in water.

(i) Oxidation- Chloroform is oxidised by oxygen present in air in the presence of light to form the toxic gas, carbonyl chloride (phosgene).

Therefore, a fully filled colored bottle of chloroform is kept in the dark so that there is no air in it and it does not get oxidised. 

(ii) Hydrolysis: Hydrolysis of chloroform by aqueous alcoholic caustic base gives sodium formate.

(iii) Addition on Acetone - The reaction of chloroform with acetone to form addition product, chloriton.

It is a nucleophilic addition reaction.

(iv) Reaction with concentrated HNO₃ Nitrification - when chloroform is heated with nitric acid Chloropicrin is formed.

Chloropicrin is a toxic liquid when chloroform is heated with nitric acid, so its vapor is used as a war gas.

(iv) as a propellant in aerosols.