42. Solving a chemistry problem

276. A weighed sample weighing m = 1.0000 g, containing lead, was dissolved in 100 ml of water, including the background electrolyte. Polarography of 5 ml of this solution resulted in a polarogram with a wave height of 10 mm. Calculate the mass fraction W of lead (IV) in percent in the analyzed sample, if during polarography of 5 ml of a standard solution with a molar concentration Cst = 0.01 mol / l of lead (II) a polarographic wave with a height hst = 20 mm was obtained.