Using an Electrolytic Capacitor to Deliver Charge to an Electrolysis Cell

A feasible use of an electrolytic capacitor to deliver charge to an electrolysis cell and quantify the product of electrolysis of water is presented. A DC power source was used to charge an electrolytic capacitor. The charge was delivered to an electrolysis cell. Electrolysis of water in the cathode and anode compartments produced OH−(aq) and H+(aq) ions, respectively. A known volume of vinegar was added to the cathode compartment. Electrolytically produced OH−(aq) neutralized the acid present in vinegar. The charging - discharging cycles were repeated and the pH was monitored after each cycle. The percentage of acetic acid (5.27%) in vinegar was determined from the equivalence point. Electrolytic titration was performed for larger volumes of vinegar and the equivalence point was determined from a visual color change of an indicator. The percentage of acetic acid was 4.82%. The percentage of acetic acid determined from the proposed electrolytic titrations was consistent with the manufacturer’s label and volumetric titration (5%). Two interdisciplinary laboratory titration experiments for the determination of acetic acid in household vinegar are presented. Consistency of the quantity of charge delivered to the electrolysis cell was independently tested for different charging voltages. The total charge required to reach the equivalence point of neutralization of standard KHP was constant (0.392 C) and consistent with the expected charge (0.390 C).