Question

Among Al₂O₃, SiO₂, P₂O₃ and SO₂ the correct order of acidic strength is:

• A. Al₂O₃ < SiO₂ < SO₂ < P₂O₃
• B. SiO₂ < SO₂ < Al₂O₃ < P₂O₃
• C. SO₂ < P₂O₃ < SiO₂ < Al₂O₃
• D. Al₂O₃ < SiO₂ < P₂O₃ < SO₂

Hint:

Acidity of oxides increases from metals to non-metals.

Answer 1

The Correct Option is D

Step 1: Nature of oxides. Al₂O₃ is amphoteric, SiO₂ is weakly acidic.
Step 2: Non-metal oxides. P₂O₃ and SO₂ are acidic oxides, SO₂ being strongest.
Step 3: Ordering acidity. Al₂O₃ < SiO₂ < P₂O₃ < SO₂