Which formula corresponds to formic acid?

Formic acid, also known as methanoic acid, has the molecular formula HCOOH. This indicates that it contains one hydrogen atom bonded to a carbon atom, which is in turn connected to both an oxygen atom through a double bond, and a hydroxyl group (–OH).

The correct choice reflects this structure accurately because it represents the functional group of a carboxylic acid, characterized by the –COOH moiety. This means the carbon atom is both part of a carbonyl group (C=O) and bonded to a hydroxyl group (–OH).

The other options do not accurately depict the structure of formic acid. For instance, the formula that indicates a carbonyl (C=O) without the additional –OH group fails to represent the complete structure of a carboxylic acid, which is essential for identifying formic acid specifically. Additionally, other formulas might represent different compounds or incomplete representations of the carboxylic acid functional group. Thus, the choice that includes both the carbonyl and hydroxyl group correctly identifies formic acid.