A new penny having a mass of 2.5133 g is dissolved in nitric acid and the resulting copper ions are plated out onto a platinum cathode that has a mass of 12.0476 g. After all the copper ions have been reduced, the measured mass at the cathode is 12.1454 g. There is no increase in mass at the anode (meaning no Pb in solution to be deposited).
What is the percent copper of the penny? (the rest is Zn, which does not plate out under these conditions and remains in solution).