A piece of magnesium ribbon is heated to redness in an atmosphere of nitrogen and on cooling with wa — s Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Heating magnesium ribbon in a nitrogen atmosphere leads to the formation of magnesium nitride: 3Mg + N2 -> Mg3N2. Step 2: When water is added to the cooled magnesium nitride, it undergoes hydrolysis to form magnesium hydroxide and release ammonia gas. Step 3: The balanced equation for hydrolysis is: Mg3N2 + 6H2O -> 3Mg(OH)2 + 2NH3. Thus, the evolved gas is ammonia, matching option (a).