38. To determine the concentration of bismuth in water

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38. To determine the concentration of bismuth in water (mg / dm3), a sample of 10.00 ml was placed in a 50.00 ml volumetric flask, acidified with dilute nitric acid, a solution of bismuthol-1 (reagent on bismuth) was added, brought to the mark with water. The optical density of the resulting solution at 440 nm in a cuvette with l = 2.0 cm was found to be 0.150.
The optical density of the standard solution obtained by treating with 1.00 ml of 0.0001 M solution of Bi (NO3) 3 * 5H2O under similar conditions is 0.200.
Calculate the concentration (mg / dm3) in water, does it exceed the MPC (MAC (Bi) = 0.50 mg / dm3)?