24. Transition Metals and Coordination Compounds
Crystal Field Theory Summary
3PRACTICE PROBLEM
Consider the following formation constant for the complexes of a certain metal M:
(1) M(H2O)62+(aq) + 3 en(aq) ⇌ M(en)32+(aq) + 6 H2O(l) Kf,1 = 8.0×1017
(2) M(H2O)62+(aq) + 6 NH3(aq) ⇌ M(NH3)62+(aq) + 6 H2O(l) Kf,2 = 4.0×108
The values indicate that M(NH3)62+ is less stable than M(en)32+. Because both reactions have 6 M−N bonds, the change in enthalpy for the two reactions (ΔH°1 and ΔH°2) should be the same. Determine which of the two reactions has the greater change in entropy. Explain.
Consider the following formation constant for the complexes of a certain metal M:
(1) M(H2O)62+(aq) + 3 en(aq) ⇌ M(en)32+(aq) + 6 H2O(l) Kf,1 = 8.0×1017
(2) M(H2O)62+(aq) + 6 NH3(aq) ⇌ M(NH3)62+(aq) + 6 H2O(l) Kf,2 = 4.0×108
The values indicate that M(NH3)62+ is less stable than M(en)32+. Because both reactions have 6 M−N bonds, the change in enthalpy for the two reactions (ΔH°1 and ΔH°2) should be the same. Determine which of the two reactions has the greater change in entropy. Explain.