2023-04-20 Acetic acid /əˈsiːtɪk/, systematically named acetic acid /ˌɛθəˈnoʊɪk/, is an acidic, colorless liquid and organic compound with the chemical formula CH3COOH (also written CH3CO2H, C2H4O2, or HC2H3O2). Vinegar contains at least 4% acetic acid, which makes acetic acid the main ingredient in vinegar be