Chapter 15, Problem 15.57P

Interpretation Introduction

Interpretation:

The $\Delta H_{\text{vap}}$ for all halogens through Trouton’s rule has to be determined.

Concept Introduction:

Molecules of liquid and solid are held together by a force of attraction. And the value of enthalpy of vaporization and sublimation reflects the magnitude of force between the molecules. Greater the value of $\Delta H_{\text{vap}}$ or $\Delta H_{\text{sub}}$, greater will be attractive force between the molecules.

If a molecule has hydrogen bonds, it increases it $\Delta H_{\text{vap}}$ because hydrogen bonds yield $\Delta H_{\text{vap}}$ of $20–40\text{ kJ}\cdot {\text{mol}}^{\text{–1}}$ approximately.