Chapter 9.8, Problem 15P

A)

Interpretation Introduction

Interpretation:

Find out the system is absorbing the heat or remains same.

Concept introduction:

The molar enthalpy of mixing $\left(\Delta \underset{\_}{H}\right)$.

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

Here, molar enthalpy of the mixture is $\underset{\_}{H}$, mole fraction of benzene is $x_1$, molar enthalpy of the benzene is ${\underset{\_}{H}}_1$, mole fraction of $\text{2-propanol}$ is $x_2$, and molar enthalpy of the $\text{2-propanol}$ is ${\underset{\_}{H}}_2$.

The mole fraction of substance $\left(x_1\right)$.

$x_1=\frac{N_1}{N_1+N_2}$ Here, number of moles of substance 1 is $N_1$, and number of moles of substance 2 is $N_2$.

The heat transfer rate is expressed $\left(\dot{Q}\right)$ as,.

$\begin{array}{c}\dot{Q}=\dot{n}\Delta \underset{\_}{H}\\ =\left({\dot{n}}_1+{\dot{n}}_2\right)\Delta \underset{\_}{H}\end{array}$

Here, molar flow rate of compound in the system is $\dot{n}$, molar flow rate of benzene in the system is ${\dot{n}}_1$, and molar flow rate of the $\text{2-propanol}$ in the system is ${\dot{n}}_2$.

B)

Interpretation Introduction

Interpretation:

Find out the system is absorbing the heat or remains same when system is consider s  ideal solution.

Concept introduction:

An ideal solution is one, in which the solvent and solute particles show the similar intermolecular interactions with each other. Solution of higher concentration or solution prepared from solvent and solute with molecular-similarity behaves as ideal solutions.

In other words, ideal solution is a solution that has thermodynamic properties similar to those of a ideal gases mixture.