Cu(en)22+ = Cu2+ + 2 en
0.1 - x x 2x
Ks = [Cu(en)22+] / [Cu2+][en]^2
Ks = ( 0.1 - x ) / 4x^3 = 10^20
所以[Cu2+] = x = 6.3 × 10^(-8)
CuY2- = Cu2+ + Y4-
0.1 -y y y
Ks = [Cu(en)22+] / [Cu2+][T4-]
( 0.1 - y ) / y^2 = 10^18.7
所以[Cu2+] = y = 1.4 × 10^(-10)
x>y,所以CuY2-更稳定.(因为电离出的Cu2+更少)