Consider the following unbalanced equation between copper(I) ions and iron to produce copper metal and iron(II) ions: Cu+ + Fe → Cu + Fe2+ What is oxidized in this reaction?

A) copper(I) ion

B) iron

C) copper

D) iron(II) ion

2 answers

Remember the definitions.
Oxidation is the loss of electrons.
So Cu goes from +1 to zero and iron goes from zero to +2. Which loses electrons?
Hi, I'm a 10th grade student and this is how I would look at it...
So what is being oxidized is what is losing electrons.

So take Copper for example.
Copper is going from a 1+ charge to no charge as a solid...so is it gaining an electron or losing.

Now think of Iron.
Iron is going from no charge to a charge of 2+. So would that be losing electrons or gaining?

Whichever element loses the electrons would be oxidized in this reaction.

Hope this helps!