Final answer:
The attractive force between the partial negative charge on the oxygen of one methanol molecule and the partial positive charge of another is known as a dipole-dipole attraction.
Step-by-step explanation:
The partial negative charge on the oxygen of a methanol molecule (CH₃OH) is attracted to the partial positive charge of another methanol molecule. This attraction is called a dipole-dipole attraction. In methanol and other polar molecules, the more electronegative oxygen atom bears a partial negative charge (designated as δ-), while the less electronegative hydrogen atoms bear partial positive charges (δ+). The attractive force between two methanol molecules arises from the interaction between the δ+ hydrogen of one molecule and the δ- oxygen of another, similar to how the hydrogen bonds form between water molecules. While not as strong as a hydrogen bond, the dipole-dipole attraction is a significant intermolecular force that contributes to the physical properties of polar substances.