Resumen de Coulometric Analysis Experiment for the Undergraduate Chemistry Laboratory
Rajeev B. Dabke, Zewdu Gebeyehu, Ryan Thor
An undergraduate experiment on coulometric analysis of four commercial household products is presented. A special type of coulometry cell made of polydimethylsiloxane (PDMS) polymer is utilized. The PDMS cell consists of multiple analyte compartments and an internal network of salt bridges. Experimental procedure for the analysis of the acid in a toilet bowl cleaner, base in household clear ammonia, Fe2+ in iron supplement tablets, and iodine in povidone–iodine is provided. Samples were titrated against coulometrically generated reagents, and the end point was detected by a visual color change of the indicator. Experimental results obtained by coulometric titration were in agreement with the results obtained by the volumetric titration and with the data on the manufacturer’s label. The experiments highlight the real-world significance of Faraday’s laws of electrolysis and the mole ratios.
