I’m really struggling on what to do for this problem

Question

Copper is electroplated from molten copper (II) chloride. A constant current of 4.00 amp is applied by an external power supply. How long, in hours, will it take to deposit 100. g of Cu

Answer 1

Cu²⁺(aq) + 2e- ==> Cu(s) This is the reaction you are interested in.

Recall:

1 amp = 1 C/s

4.00 amp = 4 C/s

So, now we need to know how many coulombs we need so we can find the number of seconds needed.

100 g Cu x 1 mol Cu/63.5 g = 1.57 moles Cu

Each mole of Cu requires 2 electrons: 1.5748 moles Cu x 2 e- / mol = 3.1496 moles e-

Each electron is = ~96,500 coulombs (C)

96,500 C / mol e- x 3.1496 mol e- = 303,937 C

303,937 C x 1 s / 4C = 75,984 s

Converting to hours we have...

75,984 sec x 1 min/60 sec x 1 hour/60 min = 21.1 hours