Chapter 6, Problem 6.65P

Interpretation Introduction

(a)

Interpretation:

Prove that the relative volatilities of species A and B is equal to the vapor ratio of vapor pressure at the system temperature.

Concept introduction:

The Raoult’s law can be written as,

$\begin{array}{l}{y}_{i}P=x_i{P}_i{}^{*}\left(T\right)\\ y_i/x_i=P_i{}^{*}\left(T\right)/P\end{array}$

Where, x and y represent mole fractions of component in liquid and vapor, P is total pressure and P* is the vapor pressure.

Interpretation Introduction

(b)

Interpretation:

Determine the relative volatility of styrene to ethylbenzene and relative volatility of benzene to ethylbenzene. Which pair is difficult to separate by distillation.

Concept introduction:

The Raoult’s law can be written as,

$\begin{array}{l}{y}_{i}P=x_i{P}_i{}^{*}\left(T\right)\\ y_i/x_i=P_i{}^{*}\left(T\right)/P\end{array}$

Where, x and y represent mole fractions of component in liquid and vapor, P is total pressure and P* is the vapor pressure.

Interpretation Introduction

(c)

Interpretation:

Prove the given expression is valid.

Concept introduction:

The Raoult’s law can be written as,

$\begin{array}{l}{y}_{i}P=x_i{P}_i{}^{*}\left(T\right)\\ y_i/x_i=P_i{}^{*}\left(T\right)/P\end{array}$

Where, x and y represent mole fractions of component in liquid and vapor, P is total pressure and P* is the vapor pressure.

Interpretation Introduction

(d)

Interpretation:

Estimate the mole fraction of benzene in the vapor phase in equilibrium with liquids having given benzene mole fractions. Calculate the total system pressure.

Concept introduction:

The Raoult’s law can be written as,

$\begin{array}{l}{y}_{i}P=x_i{P}_i{}^{*}\left(T\right)\\ y_i/x_i=P_i{}^{*}\left(T\right)/P\end{array}$

Where, x and y represent mole fractions of component in liquid and vapor, P is total pressure and P* is the vapor pressure.