The acidic, basic and amphoteric oxides, respectively, are :

Solution

Chemistry ma’am · 3 steps

Sort each oxide by its element: non-metal gives acid, active metal gives base, and Al sits in between.

1. The rule. A highly electronegative non-metal forms an acidic oxide, and an electropositive s-block metal forms a basic oxide. Borderline elements like Al, Be and Zn form amphoteric oxides that react with both acids and bases.
2. Check option (b). N₂O₃ + H₂O → 2HNO₂ gives an acid. Li₂O + H₂O → 2LiOH gives a base. Al₂O₃ dissolves in both HCl and NaOH, so it is amphoteric.

   Option	First (should be acidic)	Second (should be basic)	Third (should be amphoteric)
   (a)	Cl₂O: acidic, correct	CaO: basic, correct	P₄O₁₀: acidic, wrong
   (b)	N₂O₃: acidic, correct	Li₂O: basic, correct	Al₂O₃: amphoteric, correct
   (c)	MgO: basic, wrong	Cl₂O: acidic, wrong	Al₂O₃: amphoteric, correct
   (d)	Na₂O: basic, wrong	SO₃: acidic, wrong	Al₂O₃: amphoteric, correct

3. So. Only (b) puts all three oxides in the right order: N₂O₃ acidic, Li₂O basic and Al₂O₃ amphoteric.

The idea to keep. The more electronegative the element, the more acidic its oxide. Non-metal oxides are acidic, s-block metal oxides are basic, and borderline elements like Al, Be and Zn give amphoteric oxides.

Answer from the NTA final answer key. Solution by PrepWiser.