Mercury on heating with aqua-regia gives : — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Aqua-regia is a 3:1 mixture of concentrated HCl and concentrated HNO3, which generates nascent chlorine ([Cl]) and nitrosyl chloride (NOCl) as powerful oxidizing agents. Step 2: When mercury is treated with heated aqua-regia, it is oxidized to mercury(II) chloride (HgCl2): 3Hg + 6HCl + 2HNO3 -> 3HgCl2 + 2NO + 4H2O. Step 3: Thus, the compound formed is mercuric chloride (HgCl2), corresponding to option (b).