42. Solving a chemistry problem

180. In the determination of nickel by the addition method, a portion of the product a = 0.4828 g was dissolved, the volume of the solution was brought to 50 ml. Then 20 ml aliquots of the solution were withdrawn into 2 50 ml volumetric flasks. A standard solution of nickel was added to one of them, after which its concentration became equal to CCT=4.18*10-4 mol/l. Hydrogen peroxide was added to both flasks and the volumes were adjusted to the mark, photometrically and AS = 0.19 and AS CT = 0.39 were obtained. Calculate the percentage of nickel in the product.