8. Solving a chemistry problem

3. A sample of 0.1 g of steel containing copper was dissolved in acid, after appropriate treatment, the volume of the solution in a volumetric flask with a capacity of 25 ml was brought to the mark with water. An aliquot (5 ml) of this solution was diluted with supporting electrolyte to 25 ml. During polarography of the resulting solution, a wave with a height of 37.5 mm was recorded. Polarography of 0.5 ml of Cu2 standard solution (T=0.000064 g/ml) after dilution with background to a volume of 25 ml gave a wave height of 30 mm. Calculate the percentage of copper in steel.