Resumen de Gravimetric Analysis of Bismuth in Bismuth Subsalicylate Tablets: A Versatile Quantitative Experiment for Undergraduate Laboratories
Eric Davis, Ken Cheung, Steve Pauls, Jonathan Dick, Elijah Roth, Nicole Zalewski, Christopher Veldhuizen, Joel Coeler
In this laboratory experiment, lower- and upper-division students dissolved bismuth subsalicylate tablets in acid and precipitated the resultant Bi3+ in solution with sodium phosphate for a gravimetric determination of bismuth subsalicylate in the tablets. With a labeled concentration of 262 mg/tablet, the combined data from three different courses (general chemistry I and II and quantitative analysis) determined an average tablet concentration of 272.0 mg/tablet, with a standard deviation of ±48.46 mg. When analyzed by upper-division students, an average of 268.8 mg/tablet with a standard deviation of 16.02 mg was obtained, which confirmed the labeled concentration. In addition, students were given an opportunity to react the remaining solution with aluminum to reduce the ionic bismuth and produce a solid metal product, which reinforced the concepts of precipitation, stoichiometry, and reduction�oxidation in a single laboratory experiment.
