A mixed solution of dissolved H2S concentration of 0.01 M and containing 1.0 M NH3, 0.1 M NH4Cl is given.

a.) Find the pH and [S2-] concentration of this solution (pKb= 5.0 for NH3, pKa1=7 and pKa2=13 for H2S).

b.) How many g-Ni2+ can be dissolved in 100 mL of this solution? (pKsp=24; Ni: 58.7 gmol-1). c.) NaCN is added to the above solution so that the final [CN-]= 0.1 M. At this point, if 0.1547 g of NiSO4 is added to 100 mL of the solution, will NiS precipitate? (S:32 gmol-1, O:16 gmol-1; .. pKinst= 22).