Final answer:
To measure chloride ion concentration, a galvanic cell is constructed using an AgCl electrode as one half-cell and a copper wire as the other half-cell. The potential of the cell is measured, and by subtracting the standard electrode potential of the AgCl half-cell from the measured potential, the chloride ion concentration can be calculated.
Step-by-step explanation:
To measure the chloride ion concentration in water samples, the student constructed a galvanic cell using an AgCl electrode and a copper wire dipping into a 1.00 M CuSO4 solution.
The potential of the cell was measured to be 0.0624 V with the copper half-cell serving as the cathode. The half-cell reaction at the AgCl electrode is AgCl(s) + e- → Ag(s) + Cl-. The standard electrode potential for the AgCl half-cell is 0.2223 V, and the standard electrode potential for the copper half-cell is 0.3419 V.
By subtracting the standard electrode potential of the AgCl half-cell from the measured potential of the cell, we can calculate the concentration of chloride ions (Ksp) in the water samples.