Part A

Given the two reactions

$H_{2}S(aq)H{S}^{-}(aq)+H^{+}(aq),K_1=9\mathrm{.}33{10}^{-8},$ and

$H{S}^{-}(aq)S^{2-}(aq)+{?}^{}{H}^{+}(aq),K_2=1\mathrm{.}32{10}^{-19},$ what is the equilibrium constant $K_{\text{f}\text{i}\text{n}\text{a}\text{l}}$ for the following reaction?

$S^{2-}(aq)+2H^{+}(aq)H_{2}S(aq)$

Enter your answer numerically.

View Available Hint$($s$)$

$K_{\text{f}\text{i}\text{n}\text{a}\text{l}}=$

Part B

Given the two reactions

$3.PbC{l}_2(aq)P{b}^{2+}(aq)+2C{l}^{-}(aq),K_3=1\mathrm{.}77{10}^{-10},$ and

$4.$ AgCl$(aq)A{g}^{+}(aq)+C{l}^{-}(aq),K_4=1\mathrm{.}25{10}^{-4},$

what is the equilibrium constant $K_{\text{f}\text{i}\text{n}\text{a}\text{l}}$ for the following reaction?

$PbC{l}_2(aq)+2A{g}^{+}(aq)2$AgCl$(aq)+P{b}^{2+}(aq)$

Express your answer numerically.

View Available Hint$($s$)$

$K_{\text{f}\text{i}\text{n}\text{a}\text{l}}=$