Here's why:
* Amphoteric oxides can act as both acids and bases.
* With acids, they act as bases, accepting protons (H+) to form salts and water.
* With bases, they act as acids, donating protons (H+) to form salts and water.
Examples of amphoteric oxides:
* Aluminum oxide (Al₂O₃)
* Zinc oxide (ZnO)
* Lead(II) oxide (PbO)
* Tin(II) oxide (SnO)
Reactions:
With hydrochloric acid:
* Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O
* ZnO + 2HCl → ZnCl₂ + H₂O
With sodium hydroxide:
* Al₂O₃ + 2NaOH + 3H₂O → 2Na[Al(OH)₄]
* ZnO + 2NaOH + H₂O → Na₂[Zn(OH)₄]
Important Note: Some oxides, like those of transition metals, can exhibit amphoteric behavior depending on their oxidation state and reaction conditions.
