. A small amount of solid Hg2Cl2 and 25 ml of metallic mercury were added to a solution of 5.03 x 10-2 M NaCl. A platinum electrode immersed in the layer of mercury was connected to a reference half-cell whose electrode potential was 0.222V. The voltage of the cell was 0.121 V with the reference electrode acting as the anode. Calculate the Ksp for Hg2Cl2. ( E0 for the required half reaction = 0.797 V)