Chapter 4, Problem 4.4P

(a)

Interpretation Introduction

Interpretation:

The variation of the vapour pressure of hexane may be written as $\text{ln}\text{p}\text{=}\text{A-B/T}$, $A=15.77$ and $B=\text{}3811K$. Thus, the enthalpy of vaporization has to be determined.

Concept introduction:

The Clapeyron equation is exact and applies rigorously to all first order phase transitions. Its derivation involves approximations, in particular the assumptions that the perfect gas law holds and that the volume of condensed phases can be neglected in comparison to the volume of the gaseous phase. It can be applies only to phase transitions between the gaseous state and condensed phases.

Clausius-Clapyron equation,

$\ln \frac{P_2}{P_1}=\frac{\Delta H_{vap}}{R}\left(\frac{1}{T_2}-\frac{1}{T_1}\right)\boxed{\begin{array}{l}where,\\ \Delta H_{vap}\to Enthalpyofvaporization\\ R\to Gascons\tan t\\ P\to \mathrm{Pr}essure\\ T\to Temperature\end{array}}$

(b)

Interpretation Introduction

Interpretation:

The variation of the vapour pressure of hexane may be written as $\text{ln}\text{p}\text{=}\text{A-B/T}$, $A=15.77$ and $B=\text{}3811K$. Thus, the normal boiling point of hexane has to be determined.

Concept introduction:

The Clapeyron equation is exact and applies rigorously to all first order phase transitions. Its derivation involves approximations, in particular the assumptions that the perfect gas law holds and that the volume of condensed phases can be neglected in comparison to the volume of the gaseous phase. It can be applies only to phase transitions between the gaseous state and condensed phases.

Clausius-Clapyron equation,

$\ln \frac{P_2}{P_1}=\frac{\Delta H_{vap}}{R}\left(\frac{1}{T_2}-\frac{1}{T_1}\right)\boxed{\begin{array}{l}where,\\ \Delta H_{vap}\to Enthalpyofvaporization\\ R\to Gascons\tan t\\ P\to \mathrm{Pr}essure\\ T\to Temperature\end{array}}$