Chapter 13.4, Problem 30LC

Interpretation Introduction

Interpretation:

The substance that sublimes at or near room temperature to be molecular or ionic is to be determined.

Concept Introduction :

Without going through the liquid state, sublimation is the process by which a substance moves straight from the solid to the gas state.

Answer to Problem 30LC

Molecular substances

Explanation of Solution

In sublimation, a solid is warmed under a vacuum in sublimation equipment. The solid vaporizes and again condenses as a pure compound on a chilled surface at a lower pressure, leaving behind non-volatile residues.

Molecular compounds are covalent compounds and have van der Waals forces as intermolecular forces. The van der Waals forces are weak intermolecular forces and thus, have a relatively low boiling point. In ionic compounds, particles are held together by strong electrostatic forces of attraction, thus, they have a relatively high boiling point.

So, the substances that sublime at or near room temperature must be molecular.