Chapter 9.8, Problem 20P

Interpretation Introduction

Interpretation:

To plot the partial molar enthalpies as a function of composition for both components at both temperatures.

Concept introduction:

Partial molar enthalpy shows how the enthalpy of a solution varies with the changes in the molar composition at a constant pressure and temperature.

The partial molar enthalpy of component 1 in a mixture is given by:

${\overline{H}}_1=\underset{\_}{H}+x_2\left(\frac{d\underset{\_}{H}}{d{x}_1}\right)$

Here, molar enthalpy of the mixture is $\underset{\_}{H}$, mole fraction of component 1 and 2 is $x_1$ and $x_2$ respectively.

Similarly the partial molar enthalpy of component 2 in a mixture is given by:

${\overline{H}}_2=\underset{\_}{H}-x_1\left(\frac{d\underset{\_}{H}}{d{x}_1}\right)$

The molar enthalpy of the mixture from the pure component enthalpies and the enthalpy of mixing is expressed as:

$\underset{\_}{H}=\Delta \underset{\_}{H}+\left(x_1{\underset{\_}{H}}_1+x_2{\underset{\_}{H}}_2\right)$