The function of boiling the sodium extract with conc. HNO_(3) before testing for halogen as:

The function of boiling the sodium extract with conc. HNO_(3) before t

1.	The function of boiling the sodium extract with conc. HNO_(3) before testing for halogen as:
Answer» to make the solution acidic to make the solution clear to CONVERT `Fe^(2+)` to `Fe^(3+)` to destroy `CN^(-)` and `S^(2-)` ions Solution :If N and S are ALREADY present, they will hinder in test of halogens as `NaCN` and `Na_(2)S` will GIVE white or black precipitate with `AgNO_(3)`. Boiling conc. `HNO_(3)` is thus used to remove `CN^(-)` and `S^(2-)` ions in the FORM of volatile HCN and `H_(2)S`.