JEE PYQ: P Block Elements Question 17
Question 17 - 2021 (25 Feb Shift 2)
Which of the following compound is added to the sodium extract before addition of silver nitrate for testing of halogens?
(1) Nitric acid
(2) Sodium hydroxide
(3) Hydrochloric acid
(4) Ammonia
Show Answer
Answer: (1)
Solution
NaCN + $\text{HNO}_3 \to \text{NaNO}_3 + \text{HCN} \uparrow$. $\text{Na}_2\text{S} + \text{HNO}_3 \to \text{NaNO}_3 + \text{H}_2\text{S} \uparrow$. Nitric acid decomposes NaCN and $\text{Na}_2\text{S}$, else they precipitate in test and misquote the result.
BETA
