n. [ Carbon + oxygen + -yl. ] (Chem.) The complex radical, CO.OH, regarded as the essential and characteristic constituent which all oxygen acids of carbon (as formic, acetic, benzoic acids, etc.) have in common; -- called also oxatyl. [ 1913 Webster ]
n. (Chem.) a monovalent organic radical (written -COOH, -CO2H or -CO.OH) whose presence confers acidic properties on the compound containing it; -- called also carboxylic group. Monocarboxylic acids (such as acetic acid or butyric acid) have one carboxyl group, dicarboxylic acids (such as oxalic acid or malonic acid) have two, tricarboxylic acids (such as citric acid) have three. It is weakly acidic, the pKa of acetic acid being 4.75. [ PJC ]
adj. (Chem.) of or pertaining to the carboxyl group; having a carboxyl group (written -COOH, -CO2H or -CO.OH); as, carboxylic acids are weakly acidic. Syn. -- carboxyl. [ WordNet 1.5 ]
n. (Chem.) an organic compound whose acidity is due to the presence of a carboxyl gorup. Monocarboxylic acids (such as acetic acid or butyric acid) have one carboxyl group, dicarboxylic acids (such as oxalic acid or malonic acid) have two, tricarboxylic acids (such as citric acid) have three. [ PJC ]
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