(a) Which kind of intermolecular attractive force is shown in each case here? (b) Predict which of the four interactions is the weakest. [Section 11.2]

Key Concepts

Intermolecular Forces

Intermolecular forces are the attractive forces between molecules that influence physical properties such as boiling and melting points. The main types include hydrogen bonding, dipole-dipole interactions, and London dispersion forces. Understanding these forces is crucial for predicting how substances will behave in different states and conditions.

Hydrogen Bonding

Hydrogen bonding is a specific type of strong dipole-dipole interaction that occurs when hydrogen is covalently bonded to highly electronegative atoms like nitrogen, oxygen, or fluorine. This interaction significantly affects the properties of substances, such as water's high boiling point compared to other similar-sized molecules, making it essential for understanding molecular behavior.

Strength of Intermolecular Forces

The strength of intermolecular forces varies among the different types, with hydrogen bonds being the strongest, followed by dipole-dipole interactions, and then London dispersion forces, which are the weakest. Recognizing this hierarchy is important for predicting the physical properties of substances, such as solubility and volatility.