Galvanization

Question

I'm a little confused on how to find the mass of zinc consumed from the data:

Mass of zinc produced: .745g

Mass of Zinc electrode before 7.705g

Mass of Zinc electrode after 8.450g

Length of time cell ran: 4.00 mins.

 

Also have to calculate the number of moles of electrons that passed through the cell during the electrolysis based off the amount of zinc produced on the iron nail. Would I need to use the molar mass of zinc or iron to calculate this.

Answer 1

It seems to me that the mass of Zn consumed is given: 0.745 g.  It's strange to use the word "consumed" when it's being "produced."  As for the number of moles of electrons, Zn²⁺ + 2 e^-  -->  Zn.  So, using Faraday's Laws of electrolysis, you can calculate the number of moles of electrons.  HOWEVER, you do not state the current (i) and without that the calculation can't be done.  And it would be based on the Zn, not the Fe.

 

If you have the currect, here's how to do it:

 

Coulombs (C) = current (amps) x time (seconds)

 

C/F = moles of electrons  i.e.: C/96,500 = moles of electrons