Question

Calculate pCd2 at each of the following points in the titration of 40.00 mL of 0.0040 M Cd2 with 0.0040 M EDTA in the presence of the auxiliary complexing agent NH3. The solution is buffered at a pH of 11.00. Take the NH3 concentration to be a constant 0.100 M. The formation constant for the Cd2 -EDTA complex is given by log Kf = 16.5.

a) 0 mL
b) 3.00mL
c) 35.00 mL
d) 40.00mL
e) 45mL