Question

In copper plating, a current of 0.5A is allowed for a cathode area of 100cm2. If this current is maintained constant for 100mins, calc. the thickness of the copper deposited. [electrochemical equivalent of copper=0.00033gC-1, density of copper=10000gcm-3]

Answer 1

coulombs = current x seconds
C = 0.5A x 100 min x (60 sec/min) = 3,000 C
0.00033 g/Coulomb x 3,000 coulombs = 0.99 g Cu deposited.
Now a problem. There is no way the density of Cu is 10,000 g/cc. The density of Cu is 8.96 g/cc so I will round that off as 9 g/cc. You may have meant to round it to 10.000 g/cc.
mass Cu = volume x density
0.99 = volume x 9 g/cc
v = 0.99/9 = 0.11 cc
The area plated is 100 cm^2 or let's say 10 cm x 10 cm.
volume = length x width x thickness
0.11 = 10 x 10 x thickness. Solve for thickness. After you have corrected the problem for the density you can follow this procedure to determine the thickness. Post your work if you get stuck.