For each of the following substances, identify the intermolecular force or forces that predominate. Using your knowledge of the relative strengths of the various forces, rank the substances in order of their normal boiling points: Al2O3, F2, H2O, Br2, ICl, NaCl.

Verified step by step guidance

1. Identify the types of intermolecular forces present in each substance. For example, ionic bonds in NaCl, hydrogen bonds in H2O, London dispersion forces in F2, Br2, and ICl, and a combination of ionic and covalent in Al2O3.
2. Understand the relative strengths of these intermolecular forces. Generally, ionic bonds are the strongest, followed by hydrogen bonds, then dipole-dipole interactions, and finally London dispersion forces as the weakest.
3. Consider the molecular size and shape for substances with London dispersion forces, as larger and more complex molecules will have higher boiling points due to stronger London dispersion forces.
4. Apply the knowledge of intermolecular forces and molecular size to predict the boiling points. Substances with stronger intermolecular forces generally have higher boiling points.
5. Rank the substances based on the predicted boiling points from highest to lowest, considering the strength of the predominant intermolecular force in each substance.

Key Concepts

Intermolecular Forces

Intermolecular forces are the forces of attraction or repulsion between neighboring particles (atoms, molecules, or ions). They include hydrogen bonding, dipole-dipole interactions, and London dispersion forces. The strength of these forces significantly influences the physical properties of substances, such as boiling points, with stronger forces typically leading to higher boiling points.

Types of Intermolecular Forces

Different substances exhibit various types of intermolecular forces. For example, hydrogen bonding occurs in molecules like water (H2O), while ionic compounds like sodium chloride (NaCl) exhibit ionic bonds. Understanding the type of intermolecular forces present in each substance is crucial for predicting their boiling points and ranking them accordingly.

Boiling Point and Intermolecular Forces

The boiling point of a substance is the temperature at which its vapor pressure equals the external pressure, allowing it to transition from liquid to gas. Substances with stronger intermolecular forces require more energy to overcome these attractions, resulting in higher boiling points. Thus, analyzing the types and strengths of intermolecular forces helps in ranking substances based on their boiling points.