Chapter 6, Problem 6.75P

Interpretation Introduction

Interpretation:

The temperature at which the mixture starts to boil is to be determined. Also, the assumptions made during the calculations are to be listed. The change in temperature and the mixture composition sue to continuous heat supply is to be determined along with the temperature of the mixture when the liquid contains $15\text{ mole\%}$ methanol.

Concept introduction:

For two phase binary mixture, Raoult’s law states that,

$P=x_{\text{A}}{P}_{\text{A}}{}^{\ast }+x_{\text{B}}{P}_{\text{B}}{}^{\ast }$ .....(1)

Here, $x_{\text{A}}\text{ and }{x}_{\text{B}}$ are the mole fractions of A and B in liquid phase respectively, $P_{\text{A}}{}^{\ast }\text{ and }{P}_{\text{B}}{}^{\ast }$ are the vapor pressure of A and B respectively, and $P$ is the total pressure of the system.

Antoine equation is used to determine the vapor pressure of any substance at the given temperature by the equation:

${\log }_{10}{P}^{\ast }=A-\frac{B}{T+C}$ .....(2)

Here, $A,B\text{ and }C$ are the constants specific for a substance given in table B.4 of appendix B.