What does amphoteric mean?

What does amphoteric mean?

• A. A substance that can act as both acid and base
• B. A substance that acts only as acid
• C. A substance that acts only as base
• D. A substance that cannot react with water

Answer: (A)

Amphoteric refers to a substance that can behave as both an acid and a base depending on the reaction partner. In Bronsted-Lowry terms, it can donate a proton (act as an acid) or accept a proton (act as a base). For example, water can donate a proton to a base like NH3 to form NH4+ and OH−, and it can accept a proton from a strong acid to form H3O+. Some substances, like certain metal hydroxides (e.g., Al(OH)3), also react with both acids and bases, showing this dual behavior. So the correct idea is that the substance can act as both an acid and a base.

Amphoteric refers to a substance that can behave as both an acid and a base depending on the reaction partner. In Bronsted-Lowry terms, it can donate a proton (act as an acid) or accept a proton (act as a base). For example, water can donate a proton to a base like NH3 to form NH4+ and OH−, and it can accept a proton from a strong acid to form H3O+. Some substances, like certain metal hydroxides (e.g., Al(OH)3), also react with both acids and bases, showing this dual behavior. So the correct idea is that the substance can act as both an acid and a base.