5. (10p) (a) CO and NH3 are both strong-field ligands. However, experimental data show that in their complexes CO ligands cause higher splitting energy (A.) than NH3. How can you explain these result and give brief explanation about order of the strength of the ligands in spectrochemical series using Molecular Orbital Theory. (Sp) (b) The formation of cadmium complexes obtained from the substitution reactions of [Cd(H20)6]2+ and Br" ligand exhibits the successive equilibrium constants: logK1 = 1.56. log K2 = 0.54. log K3 = 0.06, log K. 0.37. Is this decreasing trend in successive formation constants as you expected? Write all successive substitution reactions and suggest an explanation of why K4 is larger than K3