Q5 / 90 · JEE Main 2021 (25 Feb Shift 2) · Chemistry

Which of the following compound is added to the sodium extract before addition of silver nitrate for testing of halogens?

  • Correct answer
    A
    Nitric acid
  • B
    Sodium hydroxide
  • C
    Ammonia
  • D
    Hydrochloric acid

Solution

For testing of halogens, Nitric acid is added to the sodium extract because if CN- or S2- are present then they will be oxidised and removed before the test of halides.

NaCN+HNO3→NaNO3+HCN↑
Na2S+HNO3→NaNO3+H2S↑
Nilnic acid decomposed NaCN & Na2S, else they precipitate in test & misquite the resolve

Hence, the correct answer is option: 'A'.

Relevant Questions