45. Solving a chemistry problem

518. A sample of an alloy weighing 1.6518 g was processed in an appropriate way for the determination of manganese by the persulfate-silver method and transferred to a volumetric flask with a capacity of 250 ml. For titration of 25 ml of the resulting solution, 22.1 ml of a solution of sodium arsenite-nitrite was used, the titer of which for manganese is 0.00571 g/ml. Calculate % wt. manganese in the analyzed sample.