Use the formation constant of [Au(CN)2] in Appendix K to determine the equilibrium concentration of Au+(aq) in a solution that is 0.0071 M CN and 1.1 104 M [Au(CN)2]. Is it reasonable to conclude that 100% of the gold in solution is present as the [Au(CN)2] complex ion? Explain.

The complex ion NiCL42 has two unpaired electrons, whereas Ni(CN)42 is diamagnetic. Propose structures for these two complex ions.

Ethylenediaminetetraacetate (EDTA4 ) is used as a complexing agent in chemical analysis with the structure shown in Fig. 21.7. Solutions of EDTA4 are used to treat heavy metal poisoning by removing the heavy metal in the form of a soluble complex ion. The complex ion virtually prevents the heavy metal ions from reacting with biochemical systems. The reaction of EDTA4 with Pb2+ is Pb2+(aq) + EDTA4(aq) iPbEDTA2(aq) K = 1.1 1018 Consider a solution with 0.010 mol of Pb(NO3)? added to 1.0 L of an aqueous solution buffered at pH = 13.00 and containing 0.050 M Na1EDTA. Does Pb(OH)2 precipitate from this solution? [Ksp for Pb(OH)2 = 1.2 1015.