Question

The density of copper is 8gm/cc. Number of coulombs required to plate an area of 100cm2 on both sides of thickness 0.01 using Cuso4 solution as an electrolyte

Answer 1

volume of copper=Area x thickness = 10x10 x 1/102 = 1.d = m/Vm = d x V= 8.94 x 1 = 8.94.Hence, Actual mass of Cu to be plated is 8.94 g.Now, Cu2+ + 2e- -------> CuSo, 2F --------> 63.5 g Cu       2 x 96500 C -------> 63.5g Cu                   P  C -------> 8.94 g Cu                   P = 2 x 96500 x 8.94/96500 = 27172.Hence, the answer is 27172 

Answer 2

Answer: 48630 C

Explanation: $CuSO_4\rightarrow Cu^{2+}+SO_4^{2-}$

Volume of copper to be deposited =$Area\times Thickness=100cm^2\times 0.01cm=1cm^3$  

But the deposition is to be done on both sides, thus volume=$1cm^3\times 2=2cm^3$

Density of copper= $8g/cm^3$

Mass of copper to be deposited=$Density\times Volume=8\times 2=16g$

$Cu^{2+}+2e^-\rightarrow Cu$

63.5 g of Cu is deposited by =$2\times 96500 C=193000C$ of electricity

16 g of Cu is deposited by=$\frac{193000}{63.5}\times 16=48630C$ of electricity

Thus 48630 c of electricity are required.