Amphoteric (æmˈfɒtərɪk) is a term used in chemistry to describe a substance that can act as both an acidic and a basic agent. The word is derived from the Greek amphōteros, which means "both" or "each of two." The first syllable is pronounced with the short "a" sound as in "cat," followed by the "m" sound and the "f" sound. The stress falls on the second syllable, which is pronounced with a short "o" sound as in "lot," followed by the "t" sound, the "ə" schwa sound, the "r" sound, the "ɪ" sound, and the "k" sound.
Amphoteric is an adjective used to describe a substance that can act as both an acid and a base. It refers to the characteristic of being able to react with both acidic and basic substances. When a substance is amphoteric, it possesses the ability to donate or accept protons, depending on the nature of the other substances involved in the reaction.
Amphoteric substances have the remarkable property of adjusting their behavior according to the specific conditions they are in. For example, when they are in the presence of an acidic substance, they can react as a base by accepting protons from the acid. Conversely, in the presence of a basic substance, they can react as an acid by donating protons to the base. This versatility allows amphoteric substances to form salts with both acidic and basic properties.
In chemistry, examples of amphoteric substances include certain metal oxides, hydroxides, and some amino acids. Aluminium hydroxide is an example of an amphoteric compound commonly used in antacids. Amphoteric behavior is also observed in some organic compounds, such as certain amino acids found in proteins.
Overall, the term amphoteric describes the unique ability of certain substances to exhibit behaviors or properties of both acids and bases, depending on the conditions in which they are reacting.
Having two opposite characteristics; see amphichromatic.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "amphoteric" is derived from the Greek words "ampho" meaning "both" or "of two kinds" and "teros" meaning "diverse" or "different". In chemistry, the term "amphoteric" is used to describe substances that can react as both acids and bases. The term was coined to highlight the dual nature of these substances that can exhibit both acidic and basic properties depending on the reaction conditions.