1. What is an oxide?
An oxide is a Binary compound of oxygen and another element.
M & O
Oxides can be classified in two ways –
Nature of Oxides
Amount of Oxygen present

2. 1. Types of Oxides based on their nature
Most oxides can be grouped into four types:
acidic oxides
basic oxides
amphoteric oxides
neutral oxides

3. 1. Acidic oxides React with basic oxides to produce salts
Oxides of non-metal
Acidic oxides are often gases at room temperature.
React with water to produce acids.
Example:
sulphur trioxide + water sulphuric acid
React with bases and alkalis to produce salts
Example: carbon dioxide + sodium hydroxide sodium carbonate + water
SO3 + H2O H2SO4
CO2 + 2NaOH Na2CO3 + H2O
React with basic oxides to produce salts
SiO2 + MgO MgSiO3

4. Examples of acidic oxides
Formula
Acid Produced with Water
sulphur trioxide
SO3
sulphuric acid, H2SO4
sulphur dioxide
SO2
sulphurous acid, H2SO3
carbon dioxide
CO2
carbonic acid, H2CO3
phosphorous(V) oxide
P4O10
phosphoric acid, H3PO4

6. Basic oxides Oxides of metal
Basic oxides are often solids at room temperature.
Most basic oxides are
insoluble in water.
Calcium oxide (quicklime)

7. This is a neutralisation reaction
Basic oxides
React with acids to produce salts and water only.
Example:
Magnesium oxide + hydrochloric acid magnesium chloride + water
MgO + 2HCl MgCl2 + H2O
This is a neutralisation reaction

8. Examples of basic oxides
Formula
magnesium oxide
MgO
sodium oxide
Na2O
calcium oxide
CaO
copper(II) oxide
CuO

9. Amphoteric oxides Oxides of metal Can behave as acidic oxides
or as basic oxides
Zinc oxide

10. Amphoteric oxides React with acids and alkalis to produce salts
Example: aluminium oxide (Al2O3)
aluminium oxide as a base
aluminium oxide as an acid
hydrochloric acid
aluminium chloride
water
aluminium oxide +
aluminium oxide
sodium hydroxide
sodium aluminate
water +

11. Neutral oxides
Non-metals that form oxides that show neither basic nor acidic properties.
Insoluble in water.

12. Classification based on amount of Oxygen
Normal Oxide –
These contain enough oxygen to satisfy the valence of the metal.
The oxide ion is O2-
There is only M - O bond
These can be of different types as per the valence of the metal
Monoxide – NaO, MgO
Dioxide – CO2,
Trioxide