Plating Metal - Cathode or Anode?

[meganw]

"Plating" Metal - Cathode or Anode?

Homework Statement

You want to plate out nickel from a nickel (II) nitrate solution onto a piece of metal inserted into the solution.
Should you use copper or zinc or can you use either of these metals?

Homework Equations

Standard Reduction Potentials Chart needed...

The Attempt at a Solution

Hello everyone! I understand that oxidation occurs at the anode and that eduction occurs at the cathode, but I am confused how this plating would work.

I think Ni+ needs to become Ni(s). So Ni needs to be reduced, and gain electrons. So that means that the metal inserted needs to be the anode. But I just read somewhere in my book that the cathode is the site of metal plating. :-/

My aswer would be that it needs to be Zinc.

Zn = -.76 (electrons)
Ni2+ = -.23 (empty)
Cu = .34 (electrons)

Zinc would work because Copper giving up its electrons to a higher energy level (Ni) would not be spontaneous. Is this right? (There's no answer to these problems in our Zumdahl solution manual, thanks. ) =)

Thanks!
-Megan

 

[TeethWhitener]

https://en.m.wikipedia.org/wiki/Galvanic_series
Further down on the list reduces further up on the list. So zinc will work well, and copper not so much.

There are a few mnemonics to help with remembering electrochemistry. In this case, we have “An Ox Red Cat,” or oxidation occurs at the anode while reduction occurs at the cathode. So the Ni²⁺ is reduced to nickel metal (plated) at the cathode.