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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 15
(2010) pp 178-180
Use of a Commercial Silver-Silver Chloride Electrode for the Measurement of Cell Potentials to Determine Mean Ionic Activity Coefficients
Carrie A. Kauffman, Amanda L. Muza, Michael W. Porambo, and Anderson L. Marsh*
Department of Chemistry,
Lebanon Valley College, 101 N. College Ave., Annville, PA 17003, marsh@lvc.edu
Received
September 1, 2009. Accepted December 26,
2009.
Published: 17 March 2010
Abstract. In this work, we describe the modification of the setup for a classic electrochemistry experiment in the physical chemistry laboratory, in which a commercial silver-silver chloride electrode was successfully substituted for an “in-house” fabricated one. A correction was made to the Nernst equation for the cell by accounting for the concentrated potassium chloride solution present in the electrode. A plot of the corrected cell potential versus concentration was used to more accurately determine the standard potential for the silver-silver chloride electrode. From an extrapolation to zero concentration, a value of 0.216 ± 0.002 V was calculated. This value was subsequently utilized to calculate the mean ionic activity coefficients that are in better agreement with the trend predicted using Debye-Hückel theory.
Key Words: Laboratories and Demonstrations; physical chemistry; electrochemistry
(*) Corresponding author. (E-mail: marsh@lvc.edu)
Article in PDF format (93 KB) HTML format
Supporting Materials:
A handout for students that describes the correction to the data analysis is available (19 KB).
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