Determining the Acetic Acid Concentration in White Vinegar: An At-Home Undergraduate Chemistry Experiment During the COVID-19 Pandemic

Abstract

Due to the COVID-19 pandemic, many university-level chemistry laboratory experiments transitioned online. This created an educational challenge because students are unable to access reagents and instruments typical in a university lab setting. It is also difficult for students to connect theory to practice since real-lab experimentation is not possible in a virtual online format. In our online Introductory Quantitative Analysis Laboratory course (GW Chem 2123W) in spring 2021, students were required to design and perform an experiment that could be safely conducted at home which can also demonstrate key principles of quantitative analysis. Herein, we conducted a reliable at-home experiment that utilizes university-level acid/base titration techniques to determine the acetic acid concentration in white vinegar. The experiment used sodium bicarbonate in the form of baking soda to titrate the Whole Foods white vinegar which is advertised to contain 6% of acetic acid. We reliably obtained an equivalence point for the titration from which the actual concentration of acetic acid in the vinegar was calculated with error analysis to be 19% higher than the advertised value. The analytical techniques demonstrated in this experiment supplement practical knowledge of acid/base techniques learned in the online classroom and prompt adoption of this methodology in online laboratory curriculum. This experiment can also be readily applied to measure other acidic solutions such as vinegar and juice for at-home experiment.