135. Задачка по химии №013 575

4. To determine molybdenum in steel, from a standard solution containing 0.1124 g H2MoO4•2H2O in 100 ml of solution, the following volumes were taken, and after treatment with phenylhydrazine and dilution with water to 100 ml, the following values ​​of the optical density of the solutions were obtained:
Selected volumes, ml 2 4 6 8 10
Optical density 0.05 0.11 0.16 0.21 0.25
A 1.2 g sample of steel was dissolved in acid and the solution was diluted with water to 50 ml. From 5 ml of this solution, after appropriate treatment, 100 ml of a colored solution was obtained. Its optical density was found to be 0.12.
Determine the content of molybdenum in steel (in %).

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