On heating ZnCl2.2H2O, the compound obtained is : — d and f Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Zinc chloride dihydrate (ZnCl2 . 2H2O) undergoes hydrolysis upon heating rather than simple dehydration because of the high polarizing power of the Zn2+ cation. Step 2: The water of crystallization reacts directly with the salt to release HCl gas and form zinc oxychloride, which on further heating decomposes to zinc oxide. Step 3: The overall thermal decomposition reaction is: ZnCl2 . 2H2O -> ZnO + 2HCl + H2O. Thus, the final compound obtained is ZnO, matching option (c).