During halogen test, sodium fusion extract is boiled with concentrated HNO 3 to
During halogen test, sodium fusion extract is boiled with concentrated to
remove unreacted sodium
decompose cyanide or sulphide of sodium
extract halogen from organic compound
maintain the of extract.
Solution
The sodium fusion extract is first boiled with concentrated nitric acid to decompose cyanide or sulphide of sodium formed during Lassaigne's test. These ions would otherwise interfere with silver nitrate test for halogens.