Question

In the detection test of halogen, the sodium fusion extract is acidified with _________ and then treated with __________.

• A. nitric acid, silver chloride
• B. sulphuric acid, silver nitrate
• C. nitric acid, silver nitrate
• D. sulphuric acid, silver chloride

Answer 1

Answer: (C)

nitric acid, silver nitrate

A small amount of the compound is fused with metallic sodium. The halogen present in the compound combines with sodium to form sodium halide which passes into the sodium extract.

$X+Na⟶NaX$

A part of the Lassaigne’s extract is boiled with dilute nitric acid to expel all the gases if evolved. The silver nitrate solution is added to the resulting solution.

If any of the halogen is present, a precipitate is formed.