The active ingredient of Pepto-Bismol is the compound bismuth subsalicylate, which undergoes the following dissociation when added to water:
C₇H₅BiO₄(s)+H₂O(l)⇌C₇H₄O₃₂⁻(aq)+Bi₃+(aq)+OH⁻(aq)K=?
If the maximum amount of bismuth subsalicylate that reacts by this reaction is 3.2×10⁻¹⁹ mol/L, calculate the equilibrium constant for the preceding reaction.