111. Solving a chemistry problem

111. Solving a chemistry problem

A sample of yeast (1 g) was mineralized in a mixture of sulfuric and nitric acids, lead ions were extracted, the volume of the solution was adjusted to 50 ml, and after appropriate treatment, 10 ml of a colored solution was obtained from 5 ml of this solution (the composition of the colored compound PbR). The colored compound is photometered in a cuvette with a layer thickness of 2 cm. What molar absorption coefficient should the colored compound have in order to photometer 2 ml of chloroform with 2 ml of chloroform and chloroform extract and photometer the chloroform extract in a cuvette with a layer thickness of 2 cm. What molar absorption coefficient should be for a colored compound so that with a mass fraction of lead in yeast of 4 * 10-5%, the optical density (absorptivity) would be equal to 0.020?

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