Which of the following best describes dipole-dipole forces?

• A. Forces responsible for hydrogen bonding in water.
• B. Forces between nonpolar molecules caused by temporary dipoles.
• C. Attractive forces between polar molecules due to the interaction of their permanent dipoles.
• D. Attractive forces between ions and polar molecules.

Answer: (C)

Verified step by step guidance

1. Understand that dipole-dipole forces are a type of intermolecular force that occur between molecules that have permanent dipoles, meaning the molecules are polar.
2. Recognize that these forces arise because the positive end of one polar molecule is attracted to the negative end of another polar molecule, creating an attractive interaction.
3. Differentiate dipole-dipole forces from other intermolecular forces: hydrogen bonding is a special, stronger type of dipole-dipole interaction involving H bonded to N, O, or F; London dispersion forces occur between nonpolar molecules due to temporary dipoles; ion-dipole forces occur between ions and polar molecules.
4. Conclude that the best description of dipole-dipole forces is 'Attractive forces between polar molecules due to the interaction of their permanent dipoles.'
5. Remember that this understanding helps explain properties like boiling points and solubility of polar substances.