申論題

II. Problem-solving questions, 5% for each question. Please read questions carefully, and show all work, steps, and units.
1. An analytical chemist analyzed 100.00 mL of a waste water sample that contains heavy metal ions of and . Titration of both cations in a 25.00 mL aliquot of the sample required 45.81 mL of 0.05285 M EDTA solution. Mercaptoacetic acid and ammonia were then introduced. Production of the Cu complex with the former resulted in the release of an equivalent amount of EDTA, which required a 22.85 mL titration with 0.07238 M . Calculate the concentration in ppm of and in the waste water sample. (Ni: MW= 58.693 g/mol; Cu: MW= 63.546 g/mol) (10 pt)