Chlorine gas disproportionates in hot and conc. NaOH solution. — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Phosphorus pentoxide (P4O10) is an exceptionally strong dehydrating agent. Step 2: When malonic acid, CH2(COOH)2, is heated with P4O10, it undergoes double dehydration by losing two molecules of water. Step 3: The chemical reaction is: CH2(COOH)2 - 2H2O -> C3O2. The resulting gaseous product is carbon suboxide (C3O2), which corresponds to option (b).