Organic Chemistry MCAT Practice Exam 2025 - Free MCAT Practice Questions and Study Guide

The compound with the formula CH3COOH is commonly known as acetic acid, and its IUPAC name is ethanoic acid. The name derives from the fact that acetic acid has a two-carbon chain (eth-) and contains a carboxylic acid functional group (-COOH).

In IUPAC nomenclature, the presence of the carboxylic acid group takes priority and directly influences the suffix of the compound's name, which is "-oic acid" for carboxylic acids. The two carbon atoms in the molecular structure are designated as "eth-" leading to the full name "ethanoic acid."

This compound is the most straightforward and widely recognized form of carboxylic acid, and its common presence in various contexts, including cooking (as vinegar), helps solidify its importance in both organic chemistry and daily life. Other options listed pertain to carboxylic acids with different carbon chain lengths, which are not applicable for the compound represented by the formula CH3COOH.