Which type(s) of intermolecular forces are expected between NH_3 molecules?

• A. Only London dispersion forces
• B. Hydrogen bonding and London dispersion forces
• C. Dipole-dipole forces and London dispersion forces, but not hydrogen bonding
• D. Only dipole-dipole forces

Answer: (B)

Verified step by step guidance

1. Identify the types of intermolecular forces that can exist between molecules. The main types are London dispersion forces, dipole-dipole interactions, and hydrogen bonding.
2. Examine the molecular structure of NH_3 (ammonia). It has a nitrogen atom bonded to three hydrogen atoms, and nitrogen is highly electronegative, creating a polar molecule with a significant dipole moment.
3. Determine if hydrogen bonding is possible. Hydrogen bonding occurs when hydrogen is directly bonded to highly electronegative atoms like nitrogen, oxygen, or fluorine. Since NH_3 has N-H bonds, hydrogen bonding can occur between NH_3 molecules.
4. Recognize that all molecules exhibit London dispersion forces due to temporary fluctuations in electron density, so NH_3 molecules will also have London dispersion forces.
5. Conclude that NH_3 molecules exhibit both hydrogen bonding and London dispersion forces as their intermolecular forces.