In need of any physics genius, goldfish will know i'm sure!!!

OK so we touched on oxidation and reduction in physics today, and was set this small homework for monday. As this will be one hell of a busy weekend I need to turn to you guys for help NOW!
Here goes -

"Write the equations at the anode & cathode for the electrolysis of Al2O3 & say which is reduction & which is oxidation."

HELP!!!

 

Physics?? Thats chemistry you're talking about there!

Right.

Remeber: OIL RIG. Oxidation is loss, reduction is gain. (of electrons/charge).

In electrolysis, you have the positive ions going to the cathode, and the negetive to the annode (opposite charges attract). When the ions reach the electrode, they become neutral, either losing an electron(s) or gaining them. At the annode, electron(s) are removed from the ion and put into the circuit, and at the cathode, the opposite (electron(s) are gained).

So if the Al ion is Al 3+, and the O ion is O 2-, the O goes to the annode and the Al to the cathode.

That should help I think

 

This might help...?

http://www.chem.latech.edu/~upali/chem481/chem481c6.htm

 

Thats cool

I prefer OIL RIG to LEO goes GER though Oxidation number you don't need to know till A-Level, which mcadam isn't going to do That page is good though, I'll bookmark it for my own reference

 

Goldy - wouldn't that equation include the breakdown of h2o and release of h as part of the reaction?

 

Thats a good point... yes it would (provided it was in cryolite, not pure molten aluminium oxide). If you were using carbon electrodes, the carbon would errode away on the annode to form CO2, and you would get hydrogen off at the cathode.

I think thats right?

I doubt thats going to be part of the question, if its GCSE, this sounds like the extraction of aluminium from bauxite to me... somthing I know too well

 

OIL RIG, learnt that today, lets see if I can remember it.....
Oxidation is loss, Reduction is gain - is that it???

I'll just have to ask goldfish online thanks anyway!!!