Gold penny lab

[m25]

As I was going through HS chem lab in hopes to get more used to studying experiments, I came across the famous gold penny experiment using zinc and copper to make brass alloy. In this experiment, I know that zinc gets reduced, but is the copper being oxidized?
And is the heating of "silver" looking penny to "gold" penny a redox reaction?

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[Cawolf]

Interesting. I never did this is high school.

I looked it up and it looks like you heat Zn metal with hydroxide ion?

It sounds more like the Zinc is oxidized in the hot hydroxide solution.

Then the reaction with the copper coated penny is a redox reaction where the oxidized zinc ion is reduced and plated, while the elemental zinc is oxidized.

I don't think the copper can be reduced because the potential is too low.

Then heating the zinc plated copper surface forms an alloy when the two thin layers of metal mix.

That's my take! Can't find too much scientific information on it.

 

[m25]

Interesting. I never did this is high school.

I looked it up and it looks like you heat Zn metal with hydroxide ion?

It sounds more like the Zinc is oxidized in the hot hydroxide solution.

Then the reaction with the copper coated penny is a redox reaction where the oxidized zinc ion is reduced and plated, while the elemental zinc is oxidized.

I don't think the copper can be reduced because the potential is too low.

Then heating the zinc plated copper surface forms an alloy when the two thin layers of metal mix.

That's my take! Can't find too much scientific information on it.

So in the reaction with the copper coated penny, zinc acts as both reducing and oxidizing agent? How can this even work? Does it work like a concentration cell?
And this experiment's focus is on the concept of redox reaction, but when we heat the zinc plated copper surface to make alloy, is this even a redox reaction? If not, what is it?

 

[Cawolf]

I am only making an educated guess based on a description of the procedure.

-Hydroxide and elemental Zn will form a solution of Zn2+ species - maybe bonded to O atoms?

-Putting in the copper penny makes a cell with a copper cathode and elemental zinc anode.

-The cathode reaction is the reduction of Zn2+ to Zn(s), which plates the penny (copper cathode).

-The anode reaction is the oxidation of Zn (s) to Zn2+.

I think heating the zinc plated copper will just mix the metals to form an alloy of Zn/Cu - Brass. The alloy formation sounds like a mixed crystal lattice of the two metals, not a redox reaction.