Chapter 5, Problem 5A.2AST

Interpretation Introduction

Interpretation:

The vapour pressure of water at ${\text{25}}^{\text{o}}\text{C}$ is $\text{23}\text{.76 Torr}$ and its standard enthalpy of vaporization at that temperature is $\text{44}\text{.0kJ/mol}$.  The vapour pressure of water at ${\text{35}}^{\text{o}}\text{C}$ has to be estimated.

Concept Introduction:

Clausius-Clapeyron equation:

    $\begin{array}{l}\text{ln}\frac{{\text{P}}_{\text{2}}}{{\text{P}}_{\text{1}}}\text{=}\frac{{\text{ΔH}}_{\text{vap}}^{\text{o}}}{\text{R}}\left[\frac{\text{1}}{{\text{T}}_{\text{1}}}\text{-}\frac{\text{1}}{{\text{T}}_{\text{2}}}\right]\\ {\text{ΔH}}_{\text{vap}}^{\text{o}}\text{=Enthalpy of vaporization}\\ \text{R=Universal gas constant}\\ {\text{P}}_{\text{2}}{\text{=partial pressure at temperature T}}_2\\ {\text{P}}_1{\text{=partial pressure at temperature T}}_{\text{1}}\end{array}$