carboxylic acid (thing)

A carboxylic acid is any organic acid containing the functional carboyxl group -COOH. Structurally, the group looks like:

       O=C-
         |
         OH

Carboxylic acids include:

• ascorbic acid (vitamin C)
• formic acid (which gives ant stings their bite)
• acetic acid (vinegar)
• butyric acid (which gives sweaty socks their stink)
• benzoic acid (sodium benzoate, the sodium salt of benzoic acid, is used as a food preservative)
• citric acid (which makes citrus fruits sour)

From the science dictionary at http://biotech.icmb.utexas.edu/