Definition

1. Adjective:
   • Having characteristics of both an acid and a base and capable of reacting as either: Describes a substance, typically a molecule or ion, that can behave as an acid (donating a proton, H⁺) or as a base (accepting a proton) depending on the chemical environment.

Usage and Examples

• Adjective:
  • Water is a classic example of an amphoteric substance; it can act as an acid or a base.
  • Aluminum hydroxide is amphoteric, dissolving in both acidic and basic solutions.
  • The amphoteric nature of amino acids is crucial for their behavior in biological systems.

Advanced Usage

• "Amphoteric electrolyte": A substance that can ionize to produce both hydrogen ions (H⁺) and hydroxide ions (OH⁻), or can react with both.
  • The protein acted as an amphoteric electrolyte in the buffer solution.
• "Amphoteric oxide": An oxide that can react with both acids and bases to form salts.
  • Zinc oxide is an amphoteric oxide, forming zinc salts with acids and zincates with bases.

Variants and Related Words

• Amphoterism (noun): The property of being amphoteric.
  • The amphoterism of the metal oxide was demonstrated in the laboratory.

Synonyms

• Amphiprotic: A more specific term often used interchangeably in acid-base chemistry, emphasizing the ability to both donate and accept a proton.
• Zwitterionic: Specifically describes a molecule, like an amino acid, that carries both a positive and a negative charge at different sites within the same molecule, often resulting from amphoteric behavior.

Related Scientific Concepts

• Acid-Base Reaction: A chemical reaction involving the transfer of a proton (H⁺).
• pH: A scale used to specify the acidity or basicity of an aqueous solution; amphoteric substances often exist at a specific pH called the isoelectric point.
• Isoelectric Point: The pH at which an amphoteric molecule, such as a protein or amino acid, carries no net electrical charge.

Adjective

1. having characteristics of both an acid and a base and capable of reacting as either