Chemistry: General

The Columbia Encyclopedia, 6th ed. A Dictionary of Biology Further reading

amphoterism

The Columbia Encyclopedia, 6th ed. | 2011 | Copyright

amphoterism , in chemistry, the property of certain substances of acting either as acids or as bases depending on the reaction in which they are involved. Many hydroxide compounds are amphoteric. For example, aluminum hydroxide, Al(OH) ₃ , reacts as a base with common acids to form salts, e.g., with sulfuric acid, H ₂ SO ₄ , to form aluminum sulfate, Al ₂ (SO ₄ ) ₃ . It reacts as an acid with strong bases to form aluminates, e.g., with sodium hydroxide, NaOH, to form sodium aluminate, Na[Al(OH) ₄ (OH ₂ ) ₂ ]. Organic molecules that contain both acidic (e.g., carboxyl) and basic (e.g., amino) functional groups are usually amphoteric.

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

"amphoterism." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 26 May. 2012 <http://www.encyclopedia.com>.

"amphoterism." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 26, 2012). http://www.encyclopedia.com/doc/1E1-amphotersm.html

"amphoterism." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 26, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-amphotersm.html

Learn more about citation styles

amphoteric

A Dictionary of Biology | 2004 | Copyright

amphoteric Describing a compound that can act as both an acid and a base. Amino acids, which contain both acidic and basic groups in their molecules, can be described as amphoteric. Solvents, such as water, that can both donate and accept protons are usually described as amphiprotic (see solvent).