Types of Oxides:
An oxide is a compound of oxygen and another element. Most oxides can be grouped into four types: acidic oxides, basic oxides, amphoteric oxides, and neutral oxides.
Acidic Oxides:
Non-metals may form acidic oxides. Most acidic oxides dissolve in water to form an acid. These oxides do not react with acids. However, they react with alkalis to form salt and water.
An example of acidic oxide is sulphur trioxide SO3. it is a gas which, when dissolved in water, forms Sulphuric acid H2SO4.
Basic Oxides:
The oxides of metals are basic oxides. Most basic oxides are insoluble in water. Those that are soluble are called alkalis.
Basic oxides are solids at room temperature. They react with acids to form a salt and water. They have no reaction with bases or alkalis.
An example of basic oxide is calcium oxide. It dissolves in water to form calcium hydroxide, while it reacts with hydrochloric acid or any other acid to form calcium chloride or any other salt, in addition with water.
Amphoteric Oxides:
Amphoteric oxides are metallic oxides that react with both acids and bases to form salts and water. Meaning, amphoteric oxides are oxides that contain both the abilities of acids and alkalis. If an amphoteric oxide is reacted with an acid, it will show the properties of an alkali and a neutralization reaction occurs. Similarly, if it is reacted with an alkali, it will show acidic properties and here, too, a neutralization reaction will occour.
Examples of amphoteric oxides are aluminium oxide, zinc oxide, lead (II) oxide, etc.
Neutral Oxides:
Some non-metals form oxides that show neither basic nor acidic properties. These oxides are called neutral oxides. They are insoluble in water. Some examples are carbon monoxide and nitric oxide. Water itself is also a neutral oxide.