54. Solving a chemistry problem

49. When determining the copper content in an alloy by the method of additions, a weighed portion of the alloy (msm) was transferred into a solution and the volume of the solution was brought in a volumetric flask to 50.0 ml. Aliquots of the solutions (10.0 ml) were transferred to two volumetric flasks with a capacity of 50.0 ml. A standard solution containing 100 μg of copper was added to one of them. The required amount of an aqueous solution of ammonia was introduced into both flasks, and the solutions in the flasks were brought to the mark with distilled water:
Cu2 4NH3→[Cu(NH3)4]2
Determine the mass fraction of copper in the alloy, if the following data were obtained during photometry: Ax \u003d 0.52, Ax st \u003d 0.64, (mspl) \u003d 0.4516 g.