68. In the presence of NH 3, Cu+2 forms the complex ion Cu(NH3) 4+2. If the equilibrium concentrations of Cu+2 and Cu(NH3) 4+ are 1.8 x 10-17 M and 1.0 x 10-3 M, respectively, in a 1.5 M NH3 solution, calculate the value for the overall formation constant of Cu(NH3)+2. Cu+2 + 4 NH3 -> Cu(NH3) 4+2

At 25C, 10.24 mg of Cr(OH)2 are dissolved in enough water to make 125 mL of solution. When equilibrium is established, the solution has a pH of 8.49. Estimate Ksp for Cr(OH)2.

In the presence of NH3, Cu2+ forms the complex ion Cu(NH3)42+. If the equilibrium concentrations of Cu2+ and Cu(NH3)42+ are 1.8 1017 M and 1.0 103 M, respectively, in a 1.5-M NH3 solution, calculate the value for the overall formation constant of Cu(NH3)42+. Cu2+(aq)+4NH3(aq)Cu(NH3)42+(aq)Koverall=?

What is a complex ion? The stepwise formation constants for the complex ion Cu(NH3)42+ are K1 1 103, K2 1 104, K3 = 1 103, and K4 1 103. Write the reactions that refer to each of these formation constants. Given that the values of the formation constants are large, what can you deduce about the equilibrium concentration of Cu(NH3)42+ versus the equilibrium concentration of Cu2+?