Question

Calculate the equilibrium concentration of Co^2+ in a solution with an analytical CoY^2-

concentration of 0.0200 M at pH 9.0.


Kf of CoY^2- = 2.818 x 10^16

EDTA Ka values:

Ka1=1.02 x 10^-2

Ka2=2.14 x 10^-3

Ka3=6.92 x 10^-7

Ka4=5.50 x 10^-11

Answer 1

Co2+ = CoY2-.

Co2+ = 0.02 x 2.818 x 10^16 x 1.02 x 10^-2 x 2.14 x 10^-36 x 92 x 10^-75 x 50 x 10^-11 = 5,65904e-106.