How many coulombs are required to discharge 1 mole of the following ions: Cu^2+, Na^+, Pb^2+. (1 mole of electrons = 96500 coulombs)

To solve this type of problem, first write the
half-reaction that is taking place. Then look at the number of moles of electrons
involved and then convert that to coulombs.

In the first
case:

Cu =  Cu^+2 + 2 e^-1  This means that two moles of
electrons are produced when copper is oxidized to copper +2.  Two moles of electrons is
equal to 2 moles * 96500 Coulombs/mole = 193,000 C.

Na =
Na^+1 + 1 e^-1  One mole of electrons is produced which is equal to 96,500
C

Pb = Pb ^+2  + 2 e^-1   Two moles of electrons, or
193,000 C