Changing the concentration of ligands affects the formation of a complex ion by shifting the equilibrium position of the reaction. An increase in the concentration of ligands will generally lead to the formation of more complex ions, while a decrease in the concentration of ligands will lead to the dissociation of complex ions.To calculate the concentration of the complex ion [Cu NH3 4 H2O ]2+ when 50 mL of a 0.1 M solution of ammonia is added to 50 mL of a 0.1 M solution of copper sulfate, we can use the formation constant Kf and an ICE table Initial, Change, Equilibrium to determine the equilibrium concentrations of the species involved.Initial concentrations:[Cu2+] = 0.1 M from copper sulfate [NH3] = 0.1 M from ammonia [Cu NH3 4 H2O ]2+ = 0 M initially no complex ion Since the volumes of the two solutions are equal, the final volume will be 100 mL, and the initial concentrations of Cu2+ and NH3 will be halved:[Cu2+] = 0.05 M[NH3] = 0.05 MNow, we can set up the ICE table:Cu2+ + 4NH3 <=> [Cu NH3 4 H2O ]2+Initial: 0.05 M 0.05 M 0 MChange: -x -4x +xEquilibrium: 0.05-x 0.05-4x xThe formation constant Kf is given as 1.1 x 10^12:Kf = [Cu NH3 4 H2O ]2+ / [Cu2+][NH3]^4 = 1.1 x 10^12Substitute the equilibrium concentrations from the ICE table:1.1 x 10^12 = x / 0.05 - x 0.05 - 4x ^4 This equation can be difficult to solve directly. However, since Kf is very large, we can assume that x is small compared to 0.05, so we can approximate:1.1 x 10^12 = x / 0.05 0.05 - 4x ^4 Now we can solve for x:x 1.1 x 10^12 * 0.05 0.05^4 x 1.1 x 10^12 * 1.5625 x 10^-6x 1.71875 x 10^6So, the concentration of the complex ion [Cu NH3 4 H2O ]2+ at equilibrium is approximately 1.72 x 10^6 M.