electrolytic cells (1 Viewer)

[vds700]

For each of the following electrolytic cells, label the anode and the cathode and write the half-reactions for each electrode.

1. Platinum electrodes in potassium sulfate solution.

Answer:
CATHODE- 2H2O + 2e ->H2 + 2OH-
ANODE- 2H2O -> O2 + 4H+ + 4e

2. Platinum electroes in sodium iodide solution

Answer:
CATHODE: 2H2O + 2e -> H2 + 2OH-
ANODE: 2I- -> I2 + 2e

I get completely different answers to these, so any explanations would be greatly appreciated.