PbO2 + HNO3(Conc.) -> Pb(NO3)2 + H2O + [O] — Redox Reactions and Volumetric Analysis Chemistry Question

💡 Solution & Explanation

Step 1: Lead dioxide (PbO2) is an insoluble dark brown solid. Step 2: Upon heating with concentrated nitric acid (conc. HNO3), PbO2 is reduced to Pb2+ (forming soluble lead nitrate, Pb(NO3)2) with the evolution of oxygen gas. Step 3: Since the insoluble lead dioxide is dissolved to yield a clear soluble salt solution, this is classified as a precipitate dissolution reaction (type B), corresponding to option (b).