1. Liquid-Vapor Phase Equilibrium Distillations will be performed in hood

2. Purpose To study the equilibrium of a binary non- ideal liquid-vapor system. To construct a standard curve for refractive index vs composition To construct a phase diagram. To determine the T and mol fraction of the azeotrope.

3. Liquid-Vapor Equilibrium An ideal solution obeys Raoult’s Law for all solution compositions. Water and 1- propanol are miscible but their solution does not obey Raoult’s Law. The boiling point of a binary solution depends on the composition of the solution. See Chang Chapter 5.

4. Experimental Procedure Construct a standard curve for refractive index vs solution composition. You will use a refractometer to do this. Carry out several distillations to find the boiling point of several equilibrium solutions. Construct T vs mol fraction phase diagram and find the azeotrope characteristics for the water and 1-propanol system.

5. Experimental Procedure You will carry out 11 distillations and collect a liquid and a vapor fraction for each one. Good organization, clean glassware, careful lab technique and group communication are essential for success. Assign duties to each group member before starting this experiment.