Electrochemistry R18.72 Solubility Product Constant?

Pb --------- Pb 2+ + 2 e- 0.197. PbSO 4 + 2e- -----Pb 2+ + SO4 2- . -0.308volts. Hence summing the two equations PbSO4 (s) ------Pb2+ + SO4 2- Eo = -0.111 . writing nernst equation E= Eo - 0.0591 /2 x log Pb2+ x SO4 2- uming equilibrium E = 0 Eo = 0.0591 / 2 x log K sp . -0.111=0.0591 /2 log Ksp Hence Ksp = 1.75 x 10 -4.