Three electrolytic cells containing solutions of CuNO3, Sn(NO3)2, and Fe(NO3)3, respectively, are connected in series. A current of 2.2 A is passed through the cells until 3.10 g of copper has been deposited in the cell.

(a) What masses of tin and iron are deposited?

found electron to mole ratio for each but still cant figure out what to do. thx

1 answer

96,485 coulombs will deposit 1 equivalent weight of a metal. For Cu, that is
95,485C will deposit 63.546/2= 31.77 g. The deposit was 3.10 g and that is 3.10/31.77 = 0.0976 C that flowed through the cells.
1 equivalent weight Sn = 118.71/2 = ??
1 equivalent weight Fe = 55.85/3 = 18.61
For Fe the deposit is 18.61 x 0.0976 = 1.82 g. Do the same for Sn.