A Low-Tech Laboratory Exercise to Explore Electrochemistry, Binding Coefficients and Batteries

• Naisargi Pathak ^[3] ; Marya Lieberman ^[1] ; Kimberley A Frederick ^[2] ; Ginevra A. Clark ^[3]
  1. [1] University of Notre Dame

     University of Notre Dame

     Township of Portage, Estados Unidos

     
  2. [2] Skidmore College

     Skidmore College

     City of Saratoga Springs, Estados Unidos

     
  3. [3] University Of Illinois Chicago, United States

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• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 102, Nº 11, 2025
• Idioma: inglés
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• Resumen

  • We have developed a lab for a 200-level (sophomore) analytical chemistry course that covers basic concepts of electrochemistry using a paper-based microfluidic analytical device (μPAD) system with a voltmeter. The students use wax pencils to make their own microwell and use a voltmeter to measure potentials. A key experimental advancement was the use of Play-Doh to prepare the salt bridges, significantly improving the precision and accuracy of the method. Over the course of the two-day lab, students first developed a concentration cell and measured the concentration of an unknown copper solution. Next, students used the device to determine the binding constant (Kf) of a copper-imidazole complex and designed a simple battery to light an LED. Students were able to measure potentials achieving excellent linearity over 6 orders of magnitude using this device. The concepts of electrochemistry and equilibrium introduced in the laboratory (i.e., voltaic cell, Nernst equation, concentration cell) would be suitable for a 100-level chemistry course. Student laboratory reports were examined to evaluate the learning outcomes of the laboratory. From our analysis we can demonstrate that in addition to learning electrochemistry principles, students developed troubleshooting skills.