Chapter 4, Problem 4B.12P

(a)

Interpretation Introduction

Interpretation: The change in enthalpy along a phase boundary is $\text{d}{\Delta }_{\text{trs}}H={\Delta }_{\text{trs}}{C}_p\text{d}T+\left({\Delta }_{\text{trs}}H/T\right)\text{d}T$ has to be proved.

Concept introduction: Clapeyron’s equation can be used to calculate the enthalpy of various phase transitions.  The phase transition between the two states of a substance is calculated by the following formula.

    $\left(\frac{\Delta p}{\Delta T}\right)=\frac{{\Delta }_{\text{trs}}H}{T{\Delta }_{\text{trs}}V}$

(b)

Interpretation Introduction

Interpretation: The expression $\text{d}{\Delta }_{\text{trs}}H={\Delta }_{\text{trs}}{C}_p\text{d}T+\left({\Delta }_{\text{trs}}H/T\right)\text{d}T$ can be written as $\text{d}\left({\Delta }_{\text{trs}}H/T\right)={\Delta }_{\text{trs}}{C}_p\text{dln}T$ has to be proved.

Concept introduction: Clapeyron’s equation can be used to calculate the enthalpy of various phase transitions.  The phase transition between the two states of a substance is calculated by the following formula.

    $\left(\frac{\Delta p}{\Delta T}\right)=\frac{{\Delta }_{\text{trs}}H}{T{\Delta }_{\text{trs}}V}$