Which type of intermolecular force is responsible for the attraction between the permanent dipoles of two polar molecules?

• A. Hydrogen bonding
• B. Ion-dipole interactions
• C. Dipole-dipole interactions
• D. London dispersion forces

Answer: (C)

Verified step by step guidance

1. Understand that intermolecular forces are the forces of attraction between molecules, which influence physical properties like boiling and melting points.
2. Recognize that polar molecules have permanent dipoles due to uneven distribution of electrons, resulting in partial positive and negative charges within the molecule.
3. Identify that the force responsible for attraction between the permanent dipoles of two polar molecules is called dipole-dipole interactions, where the positive end of one molecule is attracted to the negative end of another.
4. Differentiate dipole-dipole interactions from other intermolecular forces: hydrogen bonding is a special, stronger type of dipole-dipole interaction involving H bonded to N, O, or F; ion-dipole interactions occur between ions and polar molecules; London dispersion forces are weak forces present in all molecules due to temporary dipoles.
5. Conclude that since the question asks specifically about attraction between permanent dipoles of two polar molecules, the correct intermolecular force is dipole-dipole interactions.