Answer: 406 hours
Explanation:
[tex]Q=I\times t[/tex]
where Q= quantity of electricity in coloumbs
I = current in amperes = 39.5 A
t= time in seconds = ?
The deposition of copper at cathode is represented by:
[tex]Cu^{2+}+2e^-\rightarrow Cu[/tex]
[tex]96500\times 2=193000[/tex] Coloumb of electricity deposits 1 mole of copper
i.e. 63.5 g of copper is deposited by = 193000 Coloumb
Thus 19.0 kg or 19000 g of copper is deposited by = [tex]\frac{193000}{63.5}\times 19000=57748032[/tex] Coloumb
[tex]57748032=39.5\times t[/tex]
[tex]t=1461975sec=406hours[/tex] (1hour=3600s)
Thus it will take 406 hours to plate 19.0 kg of copper onto the cathode if the current passed through the cell is held constant at 39.5 A