Chapter 10, Problem 10.50SP

Interpretation Introduction

Interpretation:

The reason why ${\text{ΔH}}_{\text{vap}}$ is larger than ${\text{ΔH}}_{\text{fusion}}$ has to be given.

Concept Introduction:

Enthalpy of Vaporisation:

The amount of energy that is necessarily added to liquid substance to transform it into gaseous substance is called as enthalpy of vaporisation or heat of vaporisation.

${\text{ΔH}}_{\text{vap}}{\text{= H}}_{\text{vapour}}{\text{-H}}_{\text{liquid}}$

Here,

$\begin{array}{l}{\text{ΔH}}_{\text{vap}}\text{=}\text{change}\text{in}\text{enthalpy}\text{of}\text{vaporization}\\ \\ {\text{H}}_{\text{vapor}}\text{=}\text{enthalpy}\text{of}\text{element}\text{in}\text{gas}\text{state}\\ \\ {\text{H}}_{\text{liquid}}\text{=}\text{enthalpy}\text{of}\text{element}\text{in}\text{liquid}\text{state}\end{array}$

Enthalpy of fusion:

The amount of energy that is required to transform a substance from solid state to liquid state at constant pressure is called as enthalpy of fusion or heat of fusion.