Question:
Which of the following compound is added to the sodium extract before addition of silver nitrate for testing of halogens?
Correct Option: 1
Solution:
For testing of halogens, Nitric acid is added to the sodium extract because if $\mathrm{CN}^{-}$or $\mathrm{S}^{2-}$ are present then they will be oxidised and removed before the test of halides.