Subject: Why is the chlorine ion a stronger reducing agent than water?

To whom it may concern:

Hi! My name is Ting Li and I'm currently a grade 12 student at Sir Winston 
Churchill High School in Canada. Yesterday, during our IB chem class, we looked 
at the electrolysis of aqueous NaCl. Everyone thought that water was going to 
be oxidized and oxygen gas was going to be made at the anode. But it turns out 
that chlorine gas was made instead. Our teacher told us that in the 
electrolysis of aqueous chlorine containing ionic compounds, the chlorine ion 
would be oxidized instead of water, and that this was the one exception that we 
need to remember (because according to our reduction potential table, water is 
a stronger reducing agent than the chlorine atom). He told us that no one 
really knows why this exception occurs, and so we never found out. So would you 
possibly know the reason? Also, I was wondering what some practical 
applications of electrolysis of aqueous salts were. I know that electrolysis of 
aqueous NaCl is used now to chlorinate pools, and you can also use electrolysis 
to plate things with a layer of metal. But, are there any other applications 
besides these?

Your help would be greatly appreciated!

Thank you,

Ting Li

Re: Why is the chlorine ion a stronger reducing agent than water?