What is the common name for CH3COOH?

The common name for CH3COOH is acetic acid. This is a well-known organic compound that is primarily recognized for its use in vinegar, which typically contains around 4-8% acetic acid by volume. The structure of acetic acid features a methyl group (CH3) attached to a carboxylic acid functional group (COOH), which is characteristic of acids.

Acetic acid's IUPAC name is ethanoic acid, but it is more commonly referred to by its traditional name, acetic acid. This recognition has led to its widespread use in various applications, including food preservation, flavoring, and as a chemical reagent in the synthesis of other chemicals.

Other choices represent different organic acids: formic acid is the simplest carboxylic acid with a single carbon atom, citric acid is a tricarboxylic acid found in citrus fruits, and propanoic acid is a three-carbon carboxylic acid. While all these options are legitimate acids, they do not correspond to the molecular formula CH3COOH.