8. A 24-hr urine specimen was diluted to exactly 2.000 L. After buffering to pH 10.0, a 50.00 mL aliquot consumed 22.19 mL of 0.04481 M EDTA. The calcium in a second 50.00 mL aliquot was precipitated as CaC₂04(s), filtered, washed and redissolved in acid. Exactly 25.00 mL of the EDTA were added and the resulting solution was buffered to a pH of 10.0. The excess EDTA was back titrated with 8.31 mL of 0.05053 M MgCl₂. Calculate the milligrams of Ca²+ and Mg2+ in the original sample.

8. A 24-hr urine specimen was diluted to exactly 2.000 L. After buffering to pH 10.0, a 50.00 mL aliquot consumed 22.19 mL of 0.04481 M EDTA. The calcium in a second 50.00 mL aliquot was precipitated as CaC₂04(s), filtered, washed and redissolved in acid. Exactly 25.00 mL of the EDTA were added and the resulting solution was buffered to a pH of 10.0. The excess EDTA was back titrated with 8.31 mL of 0.05053 M MgCl₂. Calculate the milligrams of Ca²+ and Mg2+ in the original sample.

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter17: Complexation And Precipitation Reactions And Titrations

Section: Chapter Questions

Problem 17.34QAP

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