Revised surface tension lab

CHED 500

John P. Hagen III, jhagen@calpoly.edu, Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, San Luis Obispo, CA 93407 and Marc Bresler, Department of Chemistry and Biochemistry, California Polytechnic State University, 1 Grand Avenue, c/o John Hagen, San Luis Obispo, CA 93407.
Many physical chemistry lab courses include an experiment in which the students measure surface tension as a function of surfactant concentration. In the traditional experiment, the data are fit to the Gibbs isotherm to determine of the molar area for the surfactant, and the critical micelle concentration is used to calculate the free energy of micelle formation. In our experiment, the students fit their data to the Szyszkowski equation, which allows them to also calculate the free energy of surface adsorption. In addition, this experiment is the context in which the students learn to do nonlinear custom curve fitting.
 

General Papers
8:00 AM-11:45 AM, Thursday, 14 September 2006 San Francisco Marriott -- Salon 10, Oral

Division of Chemical Education

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006