Calculate the mass of ferrous ammonium sulfate you would need to add to a 100.00 mL volumetric flask to make a solution that is 59 ppm in Fe. Then, stock solution A is prepared by dissolving 183.5 mg of ferrous ammonium sulfate in water and diluting to volume in a 500-mL volumetric flask. Calculate the concentration of iron, in ppm, in stock solution A. Stock solution B is prepared by diluting 11.00 mL of stock solution A to 100.00 mL. Calculate the concentration of iron, in ppm, in stock solution B.