08. Solving a chemistry problem

268. To construct a calibration graph for the determination of cadmium, a solution of cadmium salt with a molar concentration of the equivalent of 10-4 mol/l was used, aliquots of which were diluted with an ammonium-ammonia solution with a molar concentration of the equivalent of 0.1 mol/l to 25 ml and polarographed. The following data was obtained:
V, ml 1 2 3 4 5 6
h, mm 9 15 26.5 35 41 54
A sample of the alloy a = 0.250 g containing cadmium was dissolved in nitric acid and after treatment diluted to 50 ml. When polarographing 5 ml of solution under similar conditions, the following data were obtained:
h,mm 22 22 24

Calculate the average cadmium content in the alloy.