P550: Exploring the products of electrolysis: An undergraduate laboratory experiment

Author: Rajeev B. Dabke, Columbus State University, USA

Co-Author:

Date: 8/5/14

Time: 2:25 PM2:45 PM

Room: ASH 2302

Related Symposium: S23

An undergraduate laboratory experiment for the quantitative analysis of ascorbic acid in dietary supplement tablets will be presented. The experiment combines titration concepts with stoichiometry and the perfect gas law. Electrolytically produced I3(aq) oxidized ascorbic acid in the anode compartment. Starch was used as a visual indicator to determine the end point of this reaction. Simultaneously the volume of H2(g) produced from the electrolysis of water in the cathode compartment was measured. The perfect gas law was applied to determine the amount of gas produced at the cathode. From the stoichiometric relations between the anode and cathode reactions, the amount of ascorbic acid present in a dietary tablet was determined. Detailed experimental setup, results, and the undergraduate pedagogical values will be discussed.