0731. Solving a chemistry problem

34. 25 ml of 0.1 N silver nitrate solution is poured into two glasses. The solutions are connected by a salt bridge containing potassium nitrate, and identical silver electrodes are introduced into them. 25 ml of lead nitrate solution was added to one of the glasses, resulting in a potential difference of 13 mV between the electrodes. Calculate the content of silver impurities in lead if a solution of lead nitrate is prepared by dissolving 25 g of lead in nitric acid and diluting the resulting solution to 250 ml.