- #1
oxon88
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Homework Statement
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A sphere 100 mm diameter is to be coated with chromium from a solution
containing chromium in the six valent (hexavalent) state. How much time
would be needed to produce a coating 20 μm thick if:
• the current is 20 A
• the cathodic efficiency is 15%
• the atomic weight and density of chromium are 52 and 7.2 gcm–3 respectively
Homework Equations
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(w=ItA/6F) x (efficiency (%) / 100)
The Attempt at a Solution
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Weight deposited, W =
Current, I = 20 amps
Atomic Weight, A = 52 gcm-3
Faraday's constant, F = 96500
Efficiency = 15%
sphere surface area = 4*π*502 = 31415.92mm2im not sure where to start here. can anyone advise?