The correct answer is Al2O3.
Key Points
- Al2O3 reacts with acids and bases.
- Aluminum oxide (Al2O3) is an amphoteric substance.
- The amphoteric substance is a substance that can react with both acids and bases usually to produce salt and water.
- Aluminium oxide therefore can react with both acids as well as bases. We will take the example of its reaction with hydrochloric acid (strong acid) and sodium hydroxide (strong base).
- When mixed with these two compounds aluminium oxide either acts like acid with a base and a base with an acid.
Additional Information
- Al2O3 + 6 HCl → 2 AlCl3 + 3 H2O (acts like a base)
- Al2O3 + 2 NaOH + 3 H2O → 2 NaAl(OH)4 (sodium aluminate) (acts like an acid)
- On reacting Al2O3 with HCl, we get Aluminium Chloride as the salt and water as a by-product.
- Likewise, the reaction between NaOH ( Strong Base) and Al₂O₃ results in the formation of Sodium Aluminate as salt and water.




