Carboxylic acid
![Structure of a carboxylic acid](/Images/godic/202412/18/Carboxylic-acid.svg5202.png")
![Carboxylate ion](/Images/godic/202412/18/Carboxylate-resonance-hybrid5202.png")
![3D structure of a carboxylic acid](/Images/godic/202412/18/Carboxylic-acid-group-3D5202.png")
![Carboxylic acid dimers](/Images/godic/202412/18/Carboxylic_acid_dimers5202.png")
A carboxylic acid /ˌkɑːrbɒkˈsɪlɪk/ is an organic compound that contains a carboxyl group (C(O)OH). The general formula of a carboxylic acid is R–C(O)OH, with R referring to the rest of the (possibly quite large) molecule. Carboxylic acids occur widely and include the amino acids (which make up proteins) and acetic acid (which is part of vinegar and occurs in metabolism).