Which of the following contains two amphoteric oxides?
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
Correct Answer: Option B
Explanation:
The correct answer is B. Aluminium oxide, Calcium oxide, Zinc oxide.
Here's why:
- Amphoteric oxides are oxides that can react with both acids and bases to form salts and water.
- Aluminium oxide (Al₂O₃) is amphoteric because it reacts with both acids (like hydrochloric acid) and bases (like sodium hydroxide).
- Zinc oxide (ZnO) is also amphoteric. It can react with acids to form zinc salts and with bases to form zincates.
- Calcium oxide (CaO), however, is basic, not amphoteric. It reacts with acids to form calcium salts but does not react with bases.
Thus, option B contains two amphoteric oxides: Aluminium oxide and Zinc oxide.
The other options are incorrect because they contain oxides that are either basic or acidic, not amphoteric.
The correct answer is B. Aluminium oxide, Calcium oxide, Zinc oxide.
Here's why:
- Amphoteric oxides are oxides that can react with both acids and bases to form salts and water.
- Aluminium oxide (Al₂O₃) is amphoteric because it reacts with both acids (like hydrochloric acid) and bases (like sodium hydroxide).
- Zinc oxide (ZnO) is also amphoteric. It can react with acids to form zinc salts and with bases to form zincates.
- Calcium oxide (CaO), however, is basic, not amphoteric. It reacts with acids to form calcium salts but does not react with bases.
Thus, option B contains two amphoteric oxides: Aluminium oxide and Zinc oxide.
The other options are incorrect because they contain oxides that are either basic or acidic, not amphoteric.