94. Solving a chemistry problem

22c Equal volumes of wastewater containing copper were poured into two 100 ml volumetric flasks. The necessary amounts of ammonia and a solution of rubeanic acid were also introduced there. 10.00 ml of standard copper sulfate solution (ТCuSO4/Cu=0.001) was added to one of the flasks, the contents of both flasks were brought to the mark. After filtration, the solutions were photometered, obtaining the values of the optical density Dx and Dx st to determine the concentration of copper in wastewater (g/l) ao using the following data:
V, ml 30.00
Dx 0.32
Dx st 0.47