Dissociation constant (pK2) of the buffer CHES from 5 to 55°C

CHED 300

Hannah M. Hughes, hhughes@drury.edu, Adonis Bwashi, abwashi@drury.edu, Nicholas W. Grove, ngrove@drury.edu, Sean R. LeNoue, slenoue@drury.edu, Brett T. Morris, bmorris@drury.edu, Lakshmi N. Roy, lroy@drury.edu, and Rabindra N. Roy, rroy@drury.edu. Walter H. Hoffman Department of Chemistry, Drury University, 900 N. Benton Ave., Springfield, MO 65802
The emf measurement was made by using the cell:

Pt; H2 (g, 1 atm) | CHES (m1) + NaCHESate (m2) + NaCl (m3) | AgCl, Ag

in the temperature range 5 to 55°C. The values of pK2 are reported at 5, 25, 37, and 55°C. The pK2 values will be compared with the results of other zwitterionic buffers. Thermodynamic quantities (ΔG°, ΔS°, ΔH°, and ΔCp°) have been calculated for the dissociation of the zwitterionic buffer CHES.

 

Undergraduate Research Poster Session: Analytical Chemistry
11:00 AM-1:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Chemical Education

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007