145. Solving a chemistry problem

145. Solving a chemistry problem

37. To determine the total content of heavy metals in water (lead, copper, cadmium, etc.), they are extracted from water as dithizonate complexes into carbon tetrachloride, then, after removing excess dithizone, it is treated with Hg (II) salt for conversion to dithizonate mercury photometry. The optical density of mercury dithizonate obtained by treating 500.00 ml of water is equal to 0.110 at λ = 485 nm. 500.00 ml of a standard solution containing 2.00 ml of Hg (NO3) 2 * 4H2O with T = 0.00001542 g / cm3 passed through all stages of the analysis, similarly to the test solution. The optical density of it was equal to 0,280.
What is the total content of heavy metals in water (mmol / dm3)?

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