TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

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Abstract Volume 24 (2019) pp 174-178

Simulation of pH-dependent Cyclic Voltammograms in Excel

Terje Hõim and Eugene T. Smith*

Wilkes Honors College-Florida Atlantic University, Jupiter, FL, esmith@fau.edu
Received July 29, 2019. Accepted October 30, 2019.

Published: 20 December 2019

Abstract. Proton-coupled redox reactions are modelled to reproduce pH-dependent reduction potentials. The voltammetric data of the triprotic caffeic acid as a function of pH is reproduced. The pH-dependent reduction potential for caffeic acid can be explained by a single proton coupled to electron transfer with pK_O1 = 3.4 and pK_R1 = 8.6, and E_1/2 = 0.014 V, where E_1/2 is the average reduction potential for the three ionization states. Cyclic voltammetry data of caffeic acid is modelled using a semi-differentiation approach in a spreadsheet, Excel. This article can be adapted for an advanced instrumental methods laboratory or computer lab exercise.

Key Words: Laboratories and Demonstrations; analytic chemistry

(*) Corresponding author. (E-mail: esmith@fau.edu)

Article in PDF format (274 KB) HTML format

Supporting Materials:

An Excel template used to simulate a cyclic voltammogram with a pH-dependent reduction potential due to a single proton-coupled mechanism. (196 KB)

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