Oxides
Chemistry: Cambridge International GCSE Supplement, topic 7.2.1
Oxides
An oxide is a compound of oxygen and another element. The element can be a metal or a non-metal. Oxides are formed by combustion.
Basic oxides
- Metals form metal oxides, which are basic.
- One example is sodium oxide.
- These oxides dissolve in water to form hydroxide ions.
- Na2O(s) + H2O(l) → 2NaOH(aq)
Amphoteric oxides
- Some metallic oxides are amphoteric oxides. They react with both acids and alkalis to produce salts.
- One example is aluminium oxide (Al2O3).
Acidic oxides
- Non-metals form non-metal oxides, which are acidic.
- One example is sulfur dioxide.
- These oxides are normally gases. They dissolve in water to form a mineral acid and release H+ ions.
Neutral oxides
- Some non-metal oxides are neutral oxides. They don't react with acids or alkalis.
- One example is carbon monoxide (CO).
Test yourself on Oxides
What do basic oxides form when they dissolve in water?
What is the name for a metallic oxide which reacts with both acids and alkalis to produce salts?
What do we call a non-metal oxide which doesn't react with acids or alkalis?