Question

in a sample of hydrogen iodide, what intermolecular forces exist in addition to dispersion forces?

• polar covalent bonds
• hydrogen bonding
• covalent bonds
• london dispersion forces
• dipole - dipole forces

Explanation:

Hydrogen iodide (HI) is a polar molecule (due to the electronegativity difference between H and I). Intermolecular forces: Dispersion forces exist in all molecules. Additionally, since HI is polar, dipole - dipole forces are present. Covalent bonds (polar or not) are intramolecular (within the molecule), not intermolecular. Hydrogen bonding requires H bonded to F, O, or N, which is not the case here. London dispersion forces are the same as dispersion forces, so we are looking for another force. So dipole - dipole forces are the intermolecular forces in addition to dispersion forces.

Answer:

dipole - dipole forces (the option with "dipole - dipole forces")