Modernizing Titrations in the Undergraduate Laboratory: No More Burets and End Point Confusion, Just a Top-Loading Balance and a Smartphone

This study introduces a modernized approach to classical volumetric titrations for the undergraduate chemistry curriculum. Leveraging smartphones and digital top-loading balances, we performed mass-based titrations and determined end points using digital color measurements. Our aim was to make classical wet chemistry more accessible and engaging for students. Our approach will also enable color-blind and visually impaired students to actively engage in routine laboratory procedures, such as titrations, and perform equally as well as their peers. Traditionally, titrations have relied upon manual visual detection of indicator color changes, some of which can be challenging for inexperienced students. This study used a complexometric titration with EDTA as the titrant and Eriochrome Black T (EBT) as the indicator to determine the hardness of water samples. Students used their phones/tablets to capture images of the titration process/progress, and the color digitization application (app) converted the color of the solution to red, green, and blue (RGB) values. These values were used to plot the titration curve, obtain the first and second derivatives, and determine the end point. The study demonstrated the approach was effective in determining water hardness. It showed good reproducibility and accuracy compared to the classical volumetric titrations, reducing the need for a continuous stock of glass burets. The method has the potential for broader applications and could easily be adapted for fieldwork, making it invaluable for Citizen Science type projects. The study highlights the growing role of smartphones in science education and analysis. Such technology can allow students the opportunity to bridge the gap between theory and practice and encourage creativity in experimental design.