When carboxylic acids and dicarboxylic acids have similar molecular weights, how do their melting points compare?

Explanation

The presence of an additional carboxyl group (-COOH) in dicarboxylic acids leads to stronger intermolecular forces compared to carboxylic acids. The carboxyl groups in dicarboxylic acids can form stronger hydrogen bonding interactions, as there are two hydrogen bond acceptor sites in close proximity. This enhances the overall intermolecular forces and contributes to higher melting points. Carboxylic acids, on the other hand, have weaker intermolecular forces, due to the presence of only one carboxyl group. The hydrogen bonding interactions are comparatively weaker, resulting in lower melting points. Therefore, dicarboxylic acids have greater melting points when carboxylic and dicarboxylic acids have similar molecular weights.