Q. Determine the time required to obtain a Cu deposit of thickness 1 μm when electrodeposition is done at 4 A and 6 A, respectively.
Cu atomic weight of 63.5 and its valance is 2, a Faraday of
electricity will deposit
63.5/2 = 31.75 grams of copper
But 1 amp is 60/96485 Faradays, so it will deposit 60/96485 x 31.75
= 0.0197 grams of copper
The density of copper is about 8.96 g/cm3, or 8960
g/dm3 so 1 amp current deposits about 0.0197/8960 = 2.19
x 10-6dm3
So, if the area plated is a square decimeter, the thickness plated
is 0.219 micrometer
Thickness of plating in microns = 0.219 * A/sq/dm * minutes of
plating time * current in ampere
(i) 4 A current
1 = 0.219*4*plating time in minutes
Plating time = 1.141 min
(ii) 6 A current
1 = 0.219*6*plating time in minutes
Plating time = 0.79 min
Get Answers For Free
Most questions answered within 1 hours.