Question

Which among the following is an amphoteric oxide?

• A. Na₂O
• B. CaO
• C. NO
• D. Al₂O₃

Answer 1

Answer:

D. Al₂O₃

Al₂O₃ (aluminum oxide) is an amphoteric oxide. This means it can react with both acids and bases.

• Reaction with an acid: Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O

• Reaction with a base: Al₂O₃ + 2NaOH + 3H₂O → 2Na[Al(OH)₄] (Sodium tetrahydroxoaluminate)

Because it reacts with both acids and bases, it is classified as amphoteric.