Question

Detect the presence of chlorine atom in a given organic compound p

Answer 1

Detection Of  Chlorine In organic compound :

Step1 :

Chlorine is made to react with sodium metal to form Sodium chloride .

Na + Cl ----> NaCl

Step2:
Sodium chloride on reaction with Silver nitrate gives white precipitate of Silver Chloride and sodium nitrate.

NaCl + AgNO3  ----> AgCl↓ +NaNO3

Step 3:
The precipitate formed is soluble in Ammonium hydroxide .

AgCl + 2NH₄OH ---> Ag(NH3)₂Cl +2H₂O                                 
                                      (Soluble )

Answer 2

Lassaigne’s test is used commonly for detecting the presence of halogens in an organic compound. In this method, the nitric acid is used for acidification of the sodium fusion extract. The product of this reaction is treated later using silver nitrate (AgNO₃).

The chlorine from the organic compound reacts with the sodium and form sodium chloride. When this is treated with silver nitrate, it forms silver chloride.

The reactions for this test are given below:-

Na + Cl → NaCl

NaCl + AgNO₃ → AgCl + NaNO₃

AgCl + 2NH₄OH → [Ag (NH₃)₂] Cl + 2H₂O

If the organic compounds contain sulphur or nitrogen, then the extract is subjected to boiling in order to the expel the sulphur and the nitrogen. This is important because the presence of nitrogen or sulphur might interfere with the tests for detecting halogens.