Which of the following heavy metal sulphides, obtained during systematic qualitative analysis, is pr — Qualitative and Quantitative Analysis Chemistry Question

💡 Solution & Explanation

While the sulphides of $Cu, Pb$, and $Bi$ (Group IIA) readily dissolve in hot 50% nitric acid via oxidation of the sulphide ion to elemental sulphur, Mercury(II) sulphide ($HgS$) is exceptionally stable and requires the potent combination of oxidation and complexation provided by Aqua Regia to dissolve as $HgCl_2$.