University Chemistry ›› 2015, Vol. 30 ›› Issue (4): 63-67.

• Between Teacher and Student •

Calculation of Chemical Potential in Dilute Solution and Derivation of the Osmotic Pressure Equation

Chen Feiwu, Wei Meiju, Ye Yaping, Yuan Wenxia

1. School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
• Published:2015-08-14

Abstract:

There are two ways to calculate the chemical potential of a component in solution. One is that, in the gas-liquid phase equilibrium, the chemical potential of a component in solution is equal to its corresponding chemical potential in the gas phase; thus, the chemical potential of the component in solution can be easily obtained through the gas-liquid equilibrium once its chemical potential in gas phase is known. Another way is to integrate directly the total differential of the chemical potential of the component in solution. Based on this, a new way to derive the osmotic pressure equation is presented in this article. It is also pointed out that the definitions about the osmotic pressure in some domestic physical chemistry textbooks are not reasonable and the derivation of the osmotic pressure equation is not valid.

MSC2000:

• O6