Which of the following complexes formed by `Cu^(2+)` ions is most stable ?

Options

A. (i) `Cu^(2+)+ 4NH_(3) → [Cu(NH_(3))_(4)]^(2+), logK = 11.6`
B. (ii) `Cu^(2+) + 4CN^(–) → [Cu(CN)_(4)]^(2–), logK = 27.3`
C. (iii) `Cu^(2+) + 2 en → [Cu(en)_(2)]^(2+), logK = 15.4`
D. (iv)` Cu^(2+) + 4H_(2)O → [Cu(H_(2)O)_(4)]^(2+), logK = 8.9`

Answer

B

Explanation

is most stable, higher the value of .K., more will belong K, therefore more stable will be complex.