The molecule methylamine (CH3NH2) can act as a monodentate ligand. The following are equilibrium reactions and the thermochemical data at 298 K for reactions of methylamine and en with Cd2+ (aq);

(a) Calculate ΔGo and the equilibrium constant K for the following ligand exchange reaction:

Based on the value of K in part
(a), what would you conclude about this reaction? What concept is demonstrated?
(b) Determine the magnitudes of the enthalpic (ΔHo and the entropic (-T ΔSo contributions to for the ligand exchange reaction. Explain the relative magnitudes.
(c) Based on information in this exercise and in the "A Closer Look" box on the chelate effect, predict the sign of ΔHo for the following hypothetical reaction:

Transcribed Image Text:

Cd2+(a) 4 CH3NH2(a) [Cd(CH,NH24(a) 2 en(aą) [Cd(CH3NH24(a) 4 NH3(aa) [Cd(NH3)4 (aa) 4 CH3NH2(aa)