electrochemistry question

Question

During an electroplating experiment, Copper is deposited from a CuSO₄ solution. The experiment is conducted using a current of 1.62 A for 1.0 hrs. How many grams of Copper have been deposited?

Answer 1

1.62 amperes is the same as 1.62 coulombs/sec. and you used 1 hour = 3600 seconds. Thus...

Total coulombs = 1.62 C/sec x 3600 sec = 5832 coulombs

Each mole of electrons = 1 faraday = 96,500 coulombs

Calculate moles of electrons transferred: 5832 coulombs x 1 mole e-/96500 coulombs = 0.06 moles e-

However, we have 2 moles electrons transferred for every 1 mole of Cu(s) that is deposited. So...

moles Cu(s) deposited = 0.06 moles e- x 1 mole Cu/2 moles e- = 0.03 moles Cu(s) deposited

mass of Cu deposited = 0.03 moles Cu x 63.5 g/mol = 1.9 grams of Cu deposited.