Faraday’s Law: Calculate Mass Deposited

Question

How many grams of copper metal will be deposited from a solution that contains Cu^2+ ions if a current of 0.586 A is applied for 30.7 minutes.

 ______grams

Answer 1

Cu²⁺ + 2e- ==> Cu(s)

0.586 A = 0.586 Coulombs/second (C/sec)

30.7 minutes x 60 sec/min = 1842 sec

0.586 C/sec x 1842 sec = 1079 C

1 Faraday (F) = 96,485 C/mole

moles = 1079 C x 1 mol/96485 C = 0.0112 moles e-

0.0112 moles e- x 1 mol Cu / 2 mol e = 0.00559 moles Cu

grams Cu = 0.00559 mol Cu x 63.5 g Cu/mol = 0.355 g Cu