In Problem 7.12 we looked at the successive formation constants for 1,2-diaminoethane complexes of three different metals. Using the same data, discuss the effect of the metal on the formation constant. How might the Irving–Williams series provide insight into these formation constants?

Data from Problem 7.12.

The equilibrium constants for the successive reactions of 1,2-diaminoethane with Co²⁺, Ni²⁺, and Cu²⁺ are as follows:

Discuss whether these data support the generalizations in the text about successive formation constants. How do you account for the very low value of K₃ for Cu²⁺?

Transcribed Image Text:

[M(OH₂), 1²+ + en [M(en)(OH₂), 1²+ +en [M(en) (OH₂), 1²+ + 2H₂O K₁ [M(en)₂ (OH₂)₂1²+ + 2H₂O K₂ [M(en), 1²+ + 2H₂O K₂ [M(en), (OH₂)₂1²+ +en = lon log K, Co²+ 5.89 Ni²+ 7.52 Cu²+ 10.72 log K₂ 4.83 6.28 9.31 log K 3.10 4.26 -1.0