Question: how to calculate moles of electrons passed?
Answer: The moles of electrons used = 2 x moles of Cu deposited. Moles of Cu deposited = 1.00 / 63.55 = 1.574 x 10-2 mol, so moles of electrons passed = 2 x 1.574 x 10-2 = 3.148 x 10-2 mol. From the stoichiometry of this equation, one mole of Na deposited requires the passage of one mole of electrons in the electrolysis.