Qualitative and Quantitative AnalysishardMCQ SINGLE⭐ Must-Do

An unknown, colorless gas 'X' turns moist red litmus paper blue. It produces dense white fumes when Qualitative and Quantitative Analysis Chemistry Question

Question

An unknown, colorless gas 'X' turns moist red litmus paper blue. It produces dense white fumes when brought near a glass rod dipped in concentrated $HCl$. Furthermore, passing gas 'X' through alkaline $K_2HgI_4$ yields a distinct brown precipitate. Gas 'X' is definitively identified as:

Answer: D

💡 Solution & Explanation

Turning red litmus blue indicates a basic gas. Forming white fumes with $HCl$ confirms the formation of $NH_4Cl$. The brown precipitate with alkaline $K_2HgI_4$ (Nessler's reagent) is the ultimate confirmation for Ammonia ($NH_3$).

💬
Still have doubts about this question?
Send it to our AI chemistry tutor on WhatsApp — gets answered in minutes
Ask on WhatsApp →

Practice 22,000+ questions like this

AI-adaptive practice, video lectures, and full IChO (Chemistry Olympiad) content — all in one place.

JEE Advanced · JEE Mains · NEET · IChO · AP Chemistry