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Science-Related Homework Help Physics Topic started by: lemonsplk on Mar 1, 2013



Title: What time in minutes is required to plate 2.08 grams of copper at a constant cureent flow of 1.26 Amps?
Post by: lemonsplk on Mar 1, 2013
Cu2+ + 2e- == Cu

Cu = 63.9 grams/mol

1amp= 1 coulomb/sec
1 faraday = 96,485 coulombs


Title: What time in minutes is required to plate 2.08 grams of copper at a constant cureent flow of 1.26 Amps?
Post by: micheleann on Mar 1, 2013
Reduction equation:
Cu^2+(aq) + 2e- -------> Cu(s)

Mole of Cu to be plated: 2.08 g / 63.9 g/mol = 0.0325 mol
To reduce 1 mol Cu^2+ , 2 moles of electron are rquired.
To reduce 0.0325 mol Cu^2+, 2x0.0325 = 0.065 mol electron is required.
1 mol e- carries a charge of 1 faraday, or 96485 coulombs.
0.065 mol e- carries 0.065 x 96485 = 6271.5 coulombs

Ampere = Coulomb / sec
Second = Coulomb / Ampere = 6271.5 / 1.26 = 4977.4 sec

4977.4 sec / 60 sec/min = 82.95 or 83 min