Simple and Automated Coulometric Titration of Acid Using Nonisolated Electrodes

Coulometric titrations involve the quantification of analyte by measurements of current and time. In most coulometric titrations, the anode and cathode are placed in isolated cells that are connected by a salt bridge. By contrast, the experiments described here involve coulometric titrations (of acidic protons in solution) using a silver anode and graphite cathode placed in the same reaction vessel. The chemistry of the electrode reaction generating the reactant is described. This use of non-isolated electrodes allows for simplified experimental procedures (some of which are described) and faster titration times. Additional streamlining of the experiment is achieved by the use of MicroLab data acquisition instrumentation. This laboratory is appropriate for an analytical course.