p - Block Elements Part - 5 | Class 12th

ü  Oxides: Oxides are binary compounds of oxygen with other elements.

·    Acidic oxides: They dissolve in water forming oxyacids, e.g., CO₂, SO₂, SO₃, N₂O₅, N₂O₃, P₄O₆, P₄O₁₀, Cl₂O₇, CrO₃, Mn₂O₇, V₂O₅.

Cl₂O₇ + H₂O ¾® 2 HClO₄

Mn₂O₇ + H₂O ¾® 2 HMnO₄

 

·       Basic Oxides: They either dissolve in water to form alkalies or combine with acids to form salts and water or combine with acidic oxides to form salts; e.g., Na₂O, CaO. CuO, FeO, BaO etc. Na₂O + H₂O ¾® 2 NaOH

 CaO + H₂O ¾® Ca(OH)₂

CuO + H₂SO₄ ¾® CuSO₄ + H₂O

 

·       Amphoteric Oxides: These can combine with acids as well as bases e.g., ZnO, Al₂O₃, BeO, Sb₂O₃, Cr₂O₃, PbO etc.

PbO + 2 NaOH ¾® Na₂PbO₂ + H₂O

PbO + H₂SO₄ ¾® PbSO₄ + H₂O

Cr₂O₃ + 2 NaOH ¾® Na₂Cr₂O₄ + H₂O

Cr₂O₃ + 3 H₂SO₄ ¾® Cr₂(SO₄)₃ + 3 H₂O

 

·       Neutral Oxides: They neither combine with acids nor with the bases to form salts e.g., CO, N₂O, NO etc.

·       Mixed Oxides: They behave as mixture of two simple oxides, e.g., Pb₃O₄ (2PbO + PbO₂),   Fe₃O₄ (FeO + Fe₂O₃),    Mn₃O₄ (2MnO + MnO₂).