carbonic acid, H2CO3, a weak dibasic acid (see acids and bases) formed when carbon dioxide dissolves in water; it exists only in solution. Carbonic acid forms carbonate and bicarbonate (or acid carbonate) salts (see carbonate) by reaction with bases. It contributes to the sharp taste of carbonated beverages.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.