A certain steel is to be analyzed for Cr and Mn. By suitable treatment, the Cr in
Question:
A certain steel is to be analyzed for Cr and Mn. By suitable treatment, the Cr in the steel is oxidized to Cr2O72–(aq) and the Mn to MnO4–(aq). A 10.000 g sample of steel is used to produce 250.0 mL of a solution containing Cr2O72–(aq) and MnO4–(aq). A 10.00 mL portion of this solution is added to BaCl2(aq), and by proper adjustment of the pH, the chromium is completely precipitated as BaCrO4(s); 0.549 g is obtained. A second 10.00 mL portion of the solution requires exactly 15.95 mL of 0.0750 M Fe2+(aq) for its titration in acidic solution. Calculate the % Cr and % Mn in the steel sample. In the titration MnO4–(aq) is reduced to Mn2+(aq) and Cr2O72–(aq) is reduced to Cr3+(aq); the Fe2+(aq) is oxidized to Fe3+(aq).
Step by Step Answer:
General Chemistry Principles And Modern Applications
ISBN: 9780132931281
11th Edition
Authors: Ralph Petrucci, Jeffry Madura, F. Herring, Carey Bissonnette