Question

Purification of copper can be achieved by electrorefining copper from an impure copper anode onto a pure copper cathode in an electrolytic cell. How many hours will it take to plate 14.0 kg of copper onto the cathode if the current passed through the cell is held constant at 40.0 A? Assume the copper in the electrolytic solution is present as Cu²⁺.

Answer 1

Answer: The amount of time needed to plate 14.0 kg of copper onto the cathode is 295 hours

Step-by-step explanation:

We are given:

Moles of electron = 1 mole

According to mole concept:

1 mole of an atom contains
`6.022* 10^(23)` number of particles.

We know that:

Charge on 1 electron =
`1.6* 10^(-19)C`

Charge on 1 mole of electrons =
`1.6* 10^(-19)* 6.022* 10^(23)=96500C`

`Cu^(2+)+2e^-\rightarrow Cu`

`2* 96500=193000C` is passed to deposit = 1 mole of copper

63.5 g of copper is deposited by = 193000 C

`14* 1000g=14000g` of copper is deposited by =
`(193000)/(63.5)* 14000=42551181 C`

To calculate the time required, we use the equation:

`I=(q)/(t)`

where,

I = current passed = 40.0 A

q = total charge = 42551181 C

t = time required = ?

Putting values in above equation, we get:

`40.0=(42551181 C)/(t)\\\\t=1063779sec`

Converting this into hours, we use the conversion factor:

1 hr = 3600 seconds

So,
`1063779s* (1hr)/(3600s)=295hr`

Hence, the amount of time needed to plate 14.0 kg of copper onto the cathode is 295 hours