General Electrochemistry Measurements

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Reduction Potential is a measure of how likely a material is to gain electrons.  This measurement is commonly explored in general chemistry curricula for metal-metal ion combinations and many of us are familiar with it.  By using the Model 152 Multi-EChem Half Cell Module, students can easily create a series of galvanic cells and accurately measure the stable potential created between a reference and sample metal-metal ion solutions.  From there, they can compare potentials to create a reduction potential table or vary the metal ion concentration to rediscover the Nernst equation.  All while using small sample volumes (3 mL per well) and reducing waste.

MicroLab’s Half Cell Module software provides a visual reference for students to determine the flow of electrons in oxidation-reduction reactions.  Or they can use MicroLab’s Model 125 Redox-ORP electrode to record redox titration reactions in real-time.  Data can be exported to Excel for further analysis.

 

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Potentiometric titration data of oxalate with permanganate that was exported and fit in Excel.

 

GeneralElectrochemistryElectroplating, also known as electrodeposition, is the process of using electricity to create a thin layer of metal on the surface of another conductive material.  The figure shows an example of this process in silver coating a spoon. Any metal coated material you come in contact with, such as jewelry, pennies or components of electronic devices, have undergone this process.  Electroplating gives us the ability to alter the properties of our materials and reduce manufacturing costs.  Additional resources, history, and an overview of electroplating, written by Dr. Mordechay Schlesinger, can be found here. Note: Electroplating image taken from www.nij.gov.

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MicroLab Model 272 Electroplating/Coulometry Power Supply operates with the FS-522 interface to provide a software-adjustable constant voltage (0-5V, up to 2 amps) for electroplating and electrolysis experiments. The software integrates current over time to calculate the coulombs of charge or moles of electrons delivered.  Students dry and weigh samples before and after electroplating, compare mass change to the charge transferred and determine Avagodro’s number, ionic charge or atomic mass.