General Chemistry 2: Solubility Product

By experiment, it is found that of 6.2 x 10$^{-12}$ moles of Pb$_3$(PO$_4$)$_2$ dissolves in 1 L of aqueous solution at 25$^\circ$C. What is the solubility product constant, K$_{sp}$, at this temperature?

The solubility of Ce(IO$_3$)$_3$ in a 0.20 M KIO$_3$ solution is 4.4 x 10$^{-8}$ mol/L. Calculate K$_{sp}$ for Ce(IO$_3$)$_3$.

Calculate the concentrations of Ag$^+$, Ag(S$_2$O$_3$)$^-$, and Ag(S$_2$O$_3$)$_2^{3-}$ in a solution prepared by mixing 150.0 mL of 1.00 x 10$^{-3}$ M AgNO$_3$ with 200.0 mL of 5.00 M Na$_2$S$_2$O$_3$. The stepwise formation equilibria are:

Ag$^+$ + S$_2$O$_3^{2-}$ $\leftrightharpoons$ Ag(S$_2$O$_3$)$^-$ K$_{f1}$ = 7.4 x 10$^{8}$

Ag(S$_2$O$_3$)$^-$ + S$_2$O$_3^{2-}$ $\leftrightharpoons$ Ag(S$_2$O$_3$)$_2^{3-}$ K$_{f2}$ = 3.9 x 10$^{4}$