Balancing disproportionation redox reaction

[erisedk]

Homework Statement

Complete and balance the following reaction:
Cl₂ + OH^- → Cl^- + ClO^-

Homework Equations

The Attempt at a Solution

So, I did it like any other redox:
Cl₂ + 2e^- → 2Cl^-
2Cl₂ + 4OH^- → 2ClO^- + 2H₂O + 2e^-

Net reaction: 3Cl₂ + 4OH^- → 2Cl^- + 2ClO^- + 2H₂O

However, the answer is Cl₂ + 2OH^- → Cl^- + ClO^- + H₂O

So I googled and found this: https://answers.yahoo.com/question/index?qid=20090410003712AApVw5v
But why is my method wrong?

 

[pizzasky]

The reaction you propose has six chlorine atoms on the left, but only four on the right.

 

[Borek]

2Cl₂ + 4OH^- → 2ClO^- + 2H₂O + 2e^-

If in doubt, check if elements and charge are balanced in all reactions and half reactions.

 

[erisedk]

Sorry! I balanced and rechecked everything besides Cl itself.
Thanks!