Amphoteric oxide

Amphoteric oxides are the those oxides which behave both as acidic oxides as well as basic oxides.
e.g aluminium oxide and zinc oxide. The property is known as amphoterism.
An amphoteric oxide is one that can act as either an acid or a base. Generally non-metallic oxides are acidic and metallic oxides are basic. Some non-metallic oxides are neutral and some metallic or semi metallic oxides are amphoteric. There are a number of exceptions to these generalizations.
What are amphoteric oxides?
Amphoteric oxides are the oxides that behave as both acidic and basic oxides. Amphoteric Oxides have features of acidic as well as basic oxides that neutralize both acids and bases.”"
Amphoteric oxides dissolve in water to form alkaline solutions. Alkaline solutions contain hydroxide ions. Thus aluminium oxide (Al2O3) reacts with hydrochloric acid to form aluminium chloride and water. With sodium hydroxide solution it forms sodium aluminate (NaAlO2) and water. Other common examples of amphoteric oxides include ZnO, SnO and PbO.
How to identify amphoteric oxides.
Oxides are compounds of metals or nonmetals with oxygen. There are four types of oxide. Amphoteric oxides are classified as metal oxides that react with both acids as well as bases to create salts and water. Amphoteric oxides, among many others, include lead oxide and zinc oxide. Examples include amino acids and proteins that have classes of amine and carboxylic acids and molecules that can be self-ionized, such as water.
Amphoteric oxides are oxygen compounds that show both acidic and basic characteristics. These oxides undergo a neutralisation reaction to form water and salt as they react with acid. This demonstrates the essential properties of the compounds. Similarly, the alkali reacts to the formation of salt and water, demonstrating an acidic property. "Example:" oxide of aluminium.
All of the oxides can be made by heating the element in oxygen. Reaction of aqueous solutions of the metal trihalides with hydroxide gives the oxides in hydrated form. Going down the group, there is a transition from acidic oxides, through amphoteric to basic owing to increasing metallic character of the elements concerned.
Examples of amphoteric oxides.
The word amphoteric means both of them acid and base. Amphoteric oxides have both acidic and basic properties. The oxides of aluminium and zinc are examples. They form salts when they react with acids. They also react with alkalis to form complex salts.
Examples:
ZnO(s) + 2HNO3(aq) → Zn(NO3)2(aq) + H2O(l)
ZnO(s) + 2NaOH(aq) → Na2ZnO2(aq) + H2O(l)
Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(l)
Al2O3(s) + 2NaOH(aq) → 2NaAlO2(aq) + H2O(l)
The zincates and aluminates have the ending -ate to show that their ions are compound ions containing oxygen – rather like sulfates, carbonates and nitrates, indicating ions are ZnO22- and aluminate ions are AlO2–. Ions are written as Zn(OH)42- and Al(OH)4–. Note that sodium zincate and aluminate are soluble in water.