As a chemist, I would need more information to determine the concentration of chloride ions in the seawater sample. Potentiometry involves measuring the potential difference voltage between two electrodes in a solution, which can be related to the concentration of the ion of interest. In this case, you would use a chloride-selective electrode and a reference electrode.To determine the concentration of chloride ions, you would need to perform a calibration with known chloride concentrations to create a calibration curve. This curve would relate the measured potential difference to the concentration of chloride ions. Then, you would measure the potential difference in the seawater sample and use the calibration curve to determine the concentration of chloride ions.Please provide the calibration curve data and the potential difference measured in the seawater sample, and I can help you determine the concentration of chloride ions.