CuSO4(aq.) M N + O<br>Then final products N and O are respectively. — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Passing H2S gas through acidic CuSO4 precipitates black copper(II) sulfide (CuS, compound M). CuS reacts with KCN to form copper(II) cyanide, Cu(CN)2. Step 2: Cu(CN)2 is highly unstable and spontaneously decomposes into cuprous cyanide (CuCN) and cyanogen gas ((CN)2) via a redox reaction: 2Cu(CN)2 -> 2CuCN + (CN)2. Step 3: Cuprous cyanide (CuCN) then dissolves in excess KCN to form a highly stable, soluble tetracyanocuprate(I) complex, [Cu(CN)4]3-. Therefore, the final products N and O are [Cu(CN)4]3- and (CN)2 respectively, matching option (a).