40. Solution to Chemistry Problem

16.3 The "standard addition method" was used to determine the nickel content in a biological sample. For analysis, 50.0 cm of the test solution were taken and transferred to two separatory funnels. 1.0 cm3 of a standard nickel solution with a concentration of 50 mg/dm3 was added to one of them. Nickel was extracted into the organic phase and the content in it was determined by the atomic absorption method along the nickel absorption line. Determine the nickel concentration in the analyzed sample (in mg/dm3) by calculation and graphical methods if the absorption of the nickel extract in the analyzed solution and in the solution with the addition of the standard solution is 0.650 and 0.950, respectively.