Which compound corresponds to sodium butanoate?

Sodium butanoate is the sodium salt of butanoic acid, which is a four-carbon carboxylic acid with the structure CH3-CH2-CH2-COOH. When a carboxylic acid like butanoic acid is neutralized with sodium hydroxide (NaOH), the resulting product is the sodium salt, which retains the carbon chain structure.

The correct choice reflects this structure with the specific attributes of a carboxylate ion (the conjugate base of a carboxylic acid), which is represented as the anion (–COO^-). In sodium butanoate, the butanoate ion (–C4H7O2^-) is associated with the sodium ion (Na^+).

The correct compound shows the sequence of carbon atoms: three carbon atoms connected by single bonds followed by the carboxylic group, with the sodium ion attached to the carboxylate portion. This configuration matches the expected structural formula of sodium butanoate, indicating that it includes all four carbons from butanoic acid, and accurately depicts the presence of the sodium ion. The structure includes the appropriate bonding and functional group consistent with its classification as a salt of butanoic acid