Which one of the following is an amphoteric oxide? (a) MgO (b) P4O10 (c) Na2O (d) Al2O3

Amphoteric oxides are substances that exhibit both acidic and basic behavior, reacting with both acids and bases to produce salts and water [1]. Among the given options, Sodium oxide (Na2O) and Magnesium oxide (MgO) are classified as basic oxides because they react with acids to form salts and water [1]. Phosphorus pentoxide (P4O10) is a non-metal oxide and is strictly acidic [1]. Aluminium oxide (Al2O3), however, is a classic example of an amphoteric oxide [1]. It reacts with hydrochloric acid to show its basic nature, forming aluminium chloride, and reacts with bases like sodium hydroxide to show its acidic nature, forming sodium aluminate. This dual reactivity is characteristic of metals located near the boundary between metals and non-metals in the periodic table.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > Activity 3.9 > p. 41