Question

QUESTION 13 Copper is electroplated from CuSO4 solution. A constant current of 8A is applied by an external power supply. How long will it take to deposit 100 g of Cu? The atomic mass of copper is 63.546 g/mol. F-96 485 SA/mol a. 36 h b. 12 h 607 sec d. 10.5 he e 12.2 hr

Answer 1

Mass of Copper to be deposited = 100 g Number of moles of Cu deposited = mass/mol.wt = 100 g/ (63.55 g/mol) = 1.573564 mol The deposition is Cu+2 + 2e ------> Cu Number of moles of electrons = 2 x number of moles of Cu+2 ions = 2 x 1.573564 mol = 3.147128 mol We know that 1 F = 96485 Coulombs/mol of elections 1 mole of electrons has the charge of 96485 Coulombs So, 3.147128 mol of electrons would have the charge of 96485 C/mol* 3.147128 mol = 303650.7 Coulombs We know that Charge = current x time 303650.7 Coulombs = 8 amp x time in seconds) Time = 303650.7 / 8 = 37956.33 seconds = 37956.33 /60 min = 632.6056 min = 632.6056 /60 = 10.54 hours Time = 10.5 hours Option D is the right answer.