The equilibrium constant for the dissolution of galena: PbSsolid+2H+Pbaq2++H2Saq is 9.12107 at 80C. Using the Pb2+=0.11 and H2S=1.77, calculate the equilibrium concentration of Pb2+ in aqueous solution at this temperature and at pH s of 6,5 and 4 . Assume the dissolution of galena is the only source of Pb and H2S in the solution and that there is no significant dissociation of H2S. Hint: mass balance requires that [H2S]=[Pb2+]