Structural Biochemistry/Phase Equilibria

Introduction

More than one phases coexist at the same temperature and pressure.

K-Values

K-values is a phase-equilibrium ratio, for vapor-liquid systems,

$K_i=y_i/x_i$

$y_i$ is the mole fraction of a species in vapor phase, and $x_i$ is the mole fraction of a species in liquid phase.

For ideal solutions,

$K_i=P_i^S/P$

K-values can be used for calculating bubble and dew points.

Reference

Seader, J. D., and Ernest J. Henley. Separation Process Principles. Hoboken, NJ: Wiley, 2006. Print.