JEE Advanced Chemistry: Nitrogen - Preparation Properties and Uses questions with solutions

Q1. Compound X is treated with Zn in alkaline medium (Zn/OH⁻) to produce a gas Y. Gas Y turns red litmus blue, and when Y reacts with dilute HCl, white fumes are produced. Identify X and Y respectively.

1. NaNO2 & NO
2. NaNO3 & NH3
3. Na2S & H2S
4. Na2S2O3 & SO2

Answer: NaNO3 & NH3

NH3 is the only gaseous nitrogen compound that is basic (turns red litmus blue) and produces white fumes (NH4Cl) with HCl; NaNO3 reduced by Zn/OH⁻ yields NH3.