Complex Ion Equilibria
Add all four equations together:
Hg2+ + 4I- ? HgI42-
Kf = [HgI42-]/[Hg2+][I-]4
Kf = Kf1 x Kf2 x Kf3 x Kf4 = 1.0 x 1030
Values of Kf are listed in Table 17.1; they have a wide range of values and thus of stabilities.
Unlike Bronsted-Lowrey polyprotic acids, successive Kf values may not differ by large factors, so there may be many species coexisting.