56. Solution to Chemistry Problem

14. To determine copper in the alloy, 250 cm3 of a colored solution was obtained from a 0.300 g sample after dissolution and treatment with ammonia, the optical density of which in a cuvette with a layer thickness of 1 cm was 0.250. Determine the mass fraction of copper in the alloy (in %); the molar absorption coefficient of copper ammine is 400.