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
1. Types of Oxides based on their nature Most oxides can be grouped into four types: acidic oxides basic oxides amphoteric oxides neutral oxides
1. Acidic oxides Oxides of non-metal Acidic oxides are often gases at room temperature.
Acidic oxides React with water to produce acids. Example: sulphur trioxide + water sulphuric acid SO3 + H2O H2SO4
Acidic oxides React with bases and alkalis to produce salts Example: carbon dioxide + sodium hydroxide sodium carbonate + water CO2 + 2NaOH Na2CO3 + H2O
Acidic oxides React with basic oxides to produce salts SiO2 + MgO MgSiO3
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
Basic oxides Oxides of metal Basic oxides are often solids at room temperature. Most basic oxides are insoluble in water. Calcium oxide (quicklime)
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
Examples of basic oxides Formula magnesium oxide MgO sodium oxide Na2O calcium oxide CaO copper(II) oxide CuO
Amphoteric oxides Oxides of metal Can behave as acidic oxides or as basic oxides Zinc oxide
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 +
Neutral oxides Non-metals that form oxides that show neither basic nor acidic properties. Insoluble in water.