Amphoteric Oxides - Reacting with Acids & Bases
Chemistry: Cambridge International GCSE Supplement, topic 7.2.2
Amphoteric Oxides: Reacting with Acids and Bases
Amphoteric oxides react with both acids and bases to form salt and water. Al2O3 and ZnO are key examples.
What are amphoteric oxides?
- Amphoteric oxides react with acids and bases.
- These oxides form salt and water in both reactions.
- This behaviour shows both acidic and basic properties.
- They differ from simple acidic or basic oxides.
Examples of amphoteric oxides
- Aluminium oxide, Al2O3, is an amphoteric oxide.
- Zinc oxide, ZnO, also shows amphoteric behaviour.
- Both oxides can react with hydrochloric acid (acid).
- They can also react with sodium hydroxide (base).
Aluminium oxide reactions
- Al2O3 reacts with hydrochloric acid to form aluminium chloride and water.
- Al2O3 reacts with sodium hydroxide to form sodium aluminate and water.
- These reactions demonstrate aluminium oxide's amphoteric nature.
Zinc oxide reactions
- ZnO reacts with hydrochloric acid to form zinc chloride and water.
- ZnO reacts with sodium hydroxide to form sodium zincate and water.
- These reactions confirm zinc oxide's amphoteric behaviour.
Importance of amphoteric oxides
- Amphoteric oxides show both acidic and basic characteristics.
- They help explain complex chemical behaviours.
- Emphasising Al2O3 and ZnO helps understand salt formation.
Test yourself on Amphoteric Oxides - Reacting with Acids & Bases
What does the behaviour of amphoteric oxides indicate about their properties?
When Zinc oxide (ZnO) reacts with hydrochloric acid, what salt is formed?