You extract the iron from a tablet and dilute that to 600.0 ml in a volumetric flask. You transfer 0.600 ml of this solution to a 75.0 ml volumetric flask and dilute this to volume. When you measure the concentration of this solution, you find that it is 3.78 mg Fe/L (ppm). What is the Fe of the Sample Stock Solution, in mg/L?

Question

You extract the iron from a tablet and dilute that to 600.0 ml in a volumetric flask.  You transfer 0.600 ml of this solution to a 75.0 ml volumetric flask and dilute this to volume.  When you measure the concentration of this solution, you find that it is 3.78 mg Fe/L (ppm).  What is the Fe of the Sample Stock Solution, in mg/L?

DrBob222 · Answer

3.75 mg/L is the concn of the material in the 75 mL volumetric flask. Therefore, the concn of the material in the 0.6 mL is
3.75 x 75/0.6 = ? and that is the concn of the material in the 600 mL flask (and the sample).