The Lassaigne's extract is boiled with dil. `HNO_(3)` before testing for halogens because

Options

A. Silver halides are solube in `HNO_(3)`
B. `Na_(2)S` and `NaCN` are decomposed by `HNO_(3)`
C. `Ag_(2)S` is soluble is `HNO_(3)`
D. `AgCN` is soluble is `HNO_(3)`

Answer

B

Explanation

`HNO_(3)` is added to decopose `Na_(2)S` and `NaCN` otherwise `Na_(2)S` will gie blacke pot. Of `Ag_(2)S` and `NaCN` will white ppt. of `AgCN` which would interference the test of halogens.