Question

Calculate the molar solubility of AgI in a 1.0M NH3 solution (Step by step)

Answer 1

We Know that :

      

    AgI   ? Ag⁺ + I^-               

       K_sp =[Ag⁺][I^-]    is 8.3 x10^-17

      Ag⁺ (aq) + 2NH₃ (aq) ? Ag(NH₃)₂⁺ (aq)

          K_f =[Ag(NH₃)₂⁺]/[Ag⁺][NH₃]²   is 1.5 x 10⁷

                  Total of reactions

            AgI (s) + 2NH₃ (aq) ? Ag(NH₃)₂⁺ (aq) +I^- (aq) Intial(M)                    1.0                      0.0                      0.0

Change (M)             -2s                       +s                     +s

          _______________________________________________

Equlibrium(M)         (1.0-2s)                s                         s

                        K = (K_sp)(K_f)

                            = 1.2 x 10^-9

                      K = (s)(s)/(1.0 - 2s)²

                            =  s² /(1.0)²

                   Substute K value

                     1.2 x 10^-9 =  s²/(1.0)²

                      ? s = 3.5 x 10^-5 M