Which of the following reactions is/are relevant to the microcosmic bead test? — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

Step 1: The white, sublimable substance must contain ions that sublimate, such as ammonium (NH4+) or mercury(I)/mercury(II) chlorides. Step 2: The substance gives a brown precipitate with Nessler's reagent, which is highly specific for ammonium ions (NH4+). It also gives a white precipitate with silver nitrate (AgNO3) that dissolves in ammonia, indicating chloride (Cl-). Step 3: Combining these, the substance is ammonium chloride (NH4Cl), which is a well-known sublimable salt, corresponding to option (d).