Dioxygen directly reacts with nearly all metals and non-metals except some metals (e.g., Au, Pt) and β Redox Reactions and Volumetric Analysis Chemistry Question
Question
Dioxygen directly reacts with nearly all metals and non-metals except some metals (e.g., Au, Pt) and some noble gases and form oxide(s). Oxides can be simple (e.g., MgO, Al2O3) or mixed (Pb3O4, Fe3O4). Simple oxides can be classified on the basis of their acidic, basic or amphoteric character. An oxide that combines with water to give an acid is termed acidic oxide (e.g., SO2, Cl2O7, CO2, N2O5). For example, SO2 combines with water to give H2SO3, an acid. Gaseous non-metal (A) --O2 / approp. temp.--> Pβ --O2 / room temp.--> Qβ --H2O--> R (oxy acid) + Pβ Solid non-metal (B) --O2 / approp. temp.--> Xβ --O2 / approp. catalyst & temp.--> Yβ --H2O--> Z (oxy acid) + Heat
π‘ Solution & Explanation
Step 1: Identify the initial state of the reactants. Zinc hydroxide, Zn(OH)2β, is an insoluble amphoteric white precipitate. Step 2: Observe the reaction with strong base. When excess sodium hydroxide (NaOH) is added, the precipitate reacts to form soluble sodium zincate (Na2ZnO2). Step 3: Because the insoluble precipitate dissolves to form a clear solution of a soluble complex salt, this is a precipitate dissolution reaction (type B). Thus, the correct option is (b).