What is the IUPAC name for butanoic acid?

Butanoic acid is a carboxylic acid that consists of a four-carbon alkane chain with a carboxylic acid functional group (-COOH) at one end. Its structure can be represented as CH₃(CH₂)₂COOH.

The IUPAC nomenclature for carboxylic acids involves stating the name of the corresponding alkane (butane, in this case) followed by the suffix "oic acid." Thus, the correct IUPAC name for butanoic acid is indeed butyric acid.

Butyric acid is commonly known and is often referred to by this name in both scientific and culinary contexts. The presence of the carboxylic acid group is the defining feature of its nomenclature.

The other options do not fit the criteria for naming this specific compound. Butanal is the aldehyde derived from butane, butan-1-ol is a primary alcohol, and butene refers to alkenes, which do not contain the carboxylic acid functional group. Therefore, butyric acid is the accurate and recognized IUPAC name for butanoic acid.