Question

Given...`Cu^(2+) +H_2O rarr Cu(s)+1/2O_2 + 2H^+`...where does oxidation occur?

...where does oxidation occur?

Answer 1

Oxidation occurs at the anode; whereas deposit of metallic copper occurs in the cathodic reaction.

Explanation:

At the cathode, reduction occurs:

`Cu^(2+) + 2e^(-) rarr Cu`

If it's a carbon electrode, you will see it develop a salmon-pink coloured coating of copper metal.

On the other hand, the anodic reaction features oxidation. What could be oxidized? Well, really the only candidates are the oxygen atoms of water, which is oxidized from `O^(-II)` to `O_2^(0)` in oxygen gas.

`H_2O(l) rarr 2H^(+) + 1/2O_2(g) + 2e^(-)`

The sulfate anion, `SO_4^(2-)`, is along for the ride, and does not participate in the redox process.