57 8. If 0. 581 gram of magnesium hydroxide (MM 58. 3) is added to 1 8. If gram of magnesium hydroxide (MM 58.3) is added to 1.00L of water, will it all dissolve? (Ksp = 8.9 x 10-12)Below what pH would the solution be buffered so that it does all dissolve?
58 9. Calculate the concentration of NH4+ from ammonium chloride required to prevent the precipitation of Ca(OH)2 in a liter of solution that contains 0.10 mole of ammonia and 0.10 mole of calcium ion.
59 10. If 50. mL of 0. 012M barium chloride are mixed with 25 mL of 1 10. If 50. mL of 0.012M barium chloride are mixed with 25 mL of 1.0 x 10-6M sulfuric acid, will a precipitate form?HINT: use the concentration quotient “Q” as we used it before
60 You have a aqueous solution of Zn2+ and Pb2+ both 0. 0010 M You have a aqueous solution of Zn2+ and Pb2+ both M. Both form insoluble sulfides. Approximately what pH will allow maximum precipitation of one ion and leave the other in solution?[Ksp ZnS = 2.5 x 10-22][Ksp PbS = 7 x 10-29]
68 You need to familiarize yourself with “typical” complex ions, Appendix K
69 Note that a formation constant reflects the stability of the complex.
70 13. Calculate the equilibrium constant for AgI(s) + 2NH3(aq) <===>[Ag(NH3)2]+(aq) + I-(aq)
71 14. Will 5.0 mL of 2.5 M NH3 dissolve 0.0001 mole AgCl?
72 15. A solution is prepared by adding 0. 10 mole Ni(NH3)6Cl2 to 0 15. A solution is prepared by adding 0.10 mole Ni(NH3)6Cl2 to 0.50 L of 3.0 M NH3. Calculate the [Ni(NH3)62+] and [Ni2+] in the solution.