Paper 2 · November 2013 · Acids, Bases and Salts
Which of the following Period 3 oxides is amphoteric, reacting with both acids and bases?
ASodium oxide, Na2O, a basic oxide that reacts only with acids
BAluminium oxide, Al2O3
CMagnesium oxide, MgO, a basic oxide that reacts only with acids
DSilicon dioxide, SiO2, an acidic oxide that reacts only with bases
Explanation
Al2O3 is amphoteric because it reacts with both acids (e.g. HCl) and bases (e.g. NaOH); SiO2 is acidic and Na2O/MgO are basic.
Derived from ZIMSEC Chemistry 5071/2 Paper 2 Theory, November 2013, Q2