Question

What mass of copper can be electroplated by the reaction

Cu²⁺ + 2 e^- → Cu(s)

upon passing 14.8 mA of current through a copper electrode in a Cu²⁺ solution for 161 minutes if all of the electrons that flow through the electrode react with Cu²⁺ ions to form copper atoms?
g Cu

Answer 1

the electrolysis expression is:

Cu2+ + 2e- ------> Cu

1 mol of Cu requires 2 mol of electron

1 mol of electron = 96485 C

So,1 mol of Cu requires 192970 C

let us calculate the charge passed:

t = 161.0 min = 161.0*60 s = 9660 s

time, t = 9660s

Q = I*t

= 0.0148A * 9660s

= 142.968 C

mol of Cu plated = 142.968/192970 = 0.00074 mol

Molar mass of Cu = 63.55 g/mol

mass of Cu = number of mol * molar mass

= 0.00074 * 63.55

= 0.0471g

Answer 0.0471g