Which of the following intermolecular forces plays a pivotal role in the unique properties of water?

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

Answer: (D)

Verified step by step guidance

1. Understand that water's unique properties, such as its high boiling point and surface tension, arise from specific intermolecular forces between its molecules.
2. Recall the types of intermolecular forces: ion-dipole interactions occur between ions and polar molecules, dipole-dipole interactions occur between polar molecules, London dispersion forces are present in all molecules due to temporary dipoles, and hydrogen bonding is a special, strong type of dipole-dipole interaction involving hydrogen atoms bonded to highly electronegative atoms like oxygen.
3. Recognize that in water (H\_2O), each molecule has a highly polar O-H bond, and the hydrogen atoms can form strong hydrogen bonds with the lone pairs on oxygen atoms of neighboring water molecules.
4. Identify that hydrogen bonding is stronger than typical dipole-dipole interactions and London dispersion forces, and it is this force that primarily accounts for water's anomalously high boiling point and other unique physical properties.
5. Conclude that among the listed options, hydrogen bonding is the pivotal intermolecular force responsible for water's unique properties.