Ammonia's unusually high melting point is the result of which type of intermolecular force?

• A. ionic bonding
• B. hydrogen bonding
• C. London dispersion forces
• D. dipole-dipole interactions

Answer: (B)

Verified step by step guidance

1. Identify the types of intermolecular forces listed: ionic bonding, hydrogen bonding, London dispersion forces, and dipole-dipole interactions.
2. Recall that ionic bonding occurs between ions and is not an intermolecular force but rather a strong intramolecular force in ionic compounds.
3. Understand that London dispersion forces are weak forces present in all molecules but are especially significant in nonpolar molecules.
4. Recognize that dipole-dipole interactions occur between polar molecules due to the attraction between positive and negative ends.
5. Note that hydrogen bonding is a special, stronger type of dipole-dipole interaction that occurs when hydrogen is bonded to highly electronegative atoms like nitrogen, oxygen, or fluorine, which explains ammonia's unusually high melting point.