What are amphoteric oxides? Give two examples of amphoteric oxides.

Amphoteric oxides are compounds that can act as both acidic and basic oxides, depending on the conditions in which they are placed. In other words, they can react with both acids and bases to form different compounds. Amphoteric oxides have the ability to donate or accept protons (H⁺ ions), making them versatile in their chemical reactions.

Two well-known examples of amphoteric oxides are:

1. Aluminum Oxide (Al₂O₃): Aluminum oxide is a classic example of an amphoteric oxide. It can react with both acids and bases. When it reacts with an acid, it acts as a base, neutralizing the acid and forming a salt and water. When it reacts with a base, it acts as an acid, neutralizing the base and forming a salt and water. For example:

With hydrochloric acid (HCl):
Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O

With sodium hydroxide (NaOH):
Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O

2. Zinc Oxide (ZnO): Zinc oxide is another example of an amphoteric oxide. It can also react with both acids and bases. When it reacts with an acid, it acts as a base, and when it reacts with a base, it acts as an acid. For example:

With hydrochloric acid (HCl):
ZnO + 2HCl → ZnCl₂ + H₂O

With sodium hydroxide (NaOH):
ZnO + 2NaOH → Na₂ZnO₂ + H₂O

Amphoteric oxides are important in various chemical processes and reactions, and their ability to react with both acids and bases makes them versatile compounds in both acidic and basic environments.