Chemistry - Salt Analysis Question with Solution | TestHub

The reaction of the alkaline solution ($S_1$) with Zn and KNO₃ reduces the nitrate ion to ammonia gas ($G_2=N{H}_3$). Ammonia gas reacts with Nessler's reagent ($R_1$, which is K₂[HgI₄] in KOH) to form a characteristic brown precipitate ($P_1$). This precipitate is known as the iodide of Millon's base, with the formula $N{H}_2\cdot Hg\cdot O\cdot Hg\cdot I$. Matching the options provided, the correct answer is (D).