Reactions of Chloroform:
(i) Oxidation: It undergoes oxidation in the presence of light to give highly poisonous substance called phosgene.
2CHCl3 + O2 → sunlight→ 2COCl2 + 2HCl.
(ii) Substitution: Chloroform reacts with nitric acid to form chloropicrin or nitro-chloroform. It is one of the components of tear shell.
Cl3C – H + HNO3 → Cl3C – NO2 + H2O.
(iii) Reduction: When chloroform is refluxed in the presence of zinc dust and water, chloroform is reduced to form methane.
Zn + 2H2O → Zn(OH)2 + 2[H]
CHCl3 + 6(H) → CH4 + 3HCl
(iv) Acidic Property: CHCl3 forms sodium/potassium formate by boiling with alcoholic NaOH/KOH solution.
CHCl3 + 4NaOH → H-COONa + 3NaCl + 2H2O
(v) Carbyl Amine Reaction: When chloroform is heated (60°-70°C) with aniline and caustic potash, phenyl isocyanide with extremely intolerable odour is obtained. This reaction serves as a test for chloroform or aniline identification.
Properties of Chloropicrin:
- It is an oily substance.
- It is used in tear-gas shell as it is a tear-producer.