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Percent of Manganese in the Sample

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A 0.500-g sample is analyzed spectrophotometrically for manganese by dissolving it in acid and transferring to a 250-mL flask and diluting to volume. Three aliquosts are analyzed by transferring 50-mL portions with a pipet to 500-mL Erirnmeyer flasks and reacting with an oxidizing agent, potasium peroxydisulfate, to convert the manganese to permanaganate. After reaction, they are quantitatively trnasferred to 250-mL volumetric flasks, diluted to volume, and measured spectrophotometrically. By comparison to standards, the average concentration in the final solution is determined to be 1.25 x 10^-5 M. What is the percent of manganese in the sample?

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For this question, you have two dilutions (from what I understand). A 10:1 dilution, and a 5:1 dilution. We have the final concentration of 1.25 x10^-5 M.

We need to back dilute (undilute).

using C1V1 = C2V2 we should be able to accurately do ...

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