How to decide which one is getting oxidized/reduced

[Sammy1024]

If you're given a question where it just lists stuff like Cu2+ Cu Zn2+ Zn and then asks you to write out the equation where it'll be like

Zn2+ + Cu -> Zn + Cu2+

How do you decide if the Zinc should be charged first and goes to being 0 charge or the Copper?

And then as a side note, e- go anode to cathode and so that's no matter what right? Doesn't matter if it's galvanic or electrochemical cell?

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[Teleologist]

And then as a side note, e- go anode to cathode and so that's no matter what right? Doesn't matter if it's galvanic or electrochemical cell?

Well opposites attract so what do you think?

 

[SuperSneaky24]

I believe if you're just given those elements/ions without a table of electric potentials, then it's going to be difficult.

And yup you're correct. Reduction always occurs at the cathode, while oxidation always occurs at the anode. The anodes/cathodes are simply switch sides between galvanic and electrolytic cells. That means electrons always go from the site of oxidation to the site of reduction, and thus go from anode to cathode always.