If you have a solution containing 0.10 M Fe+3 and 0.10 M Ca+2 and you want to titrate the Fe+3 with EDTA, how much error is there due to the reaction of Ca+2 with the EDTA at the Fe+3 equivalence point if you titrate at the following pHs.
3.0
6.0
10.0
At what pH would you titrate the Fe+3?