Question

n order to determine the concentration of bivalent nickel in environmental samples we can use the complexometric titration. A 100 mL sample containing Ni2 + was treated with 50 mL of 0.02 mol / L EDTA solution complexing all Ni2 + solution and leaving an excess of EDTA in the solution for subsequent retro-titration with a standard of Zn2 + 0.05 mol / L . In the retro-titration, 10 mL of standard Zn2 + solution was expended until the titration endpoint. Determine the nickel concentration in the sample

Answer 1

mols EDTA total = M x L = ?
,p;s EDTA back titrated = ?
Difference is mols Ni and (Ni^2+) = mols/L
I assume you know that EDTA complexes with both Zn and Ni 1:1