Redox Question

For me personally, I like to use the "OIL RIG" instead of "LEO GER", I just remember it better...

Oxidation is loss of e-
Reduction is gain of e-

We also know that "RED CAT, AN OX", so reduction at the cathode, oxidation at the anode.

So reduction at the cathode is gain of e- so an example would be...

Al+3 + 3e- ----> Al

And oxidation at the anode is loss of e- so example would be....

2Cl ----> Cl2 + 2e-

REMEMBER: anions will go to anode. cations will go to cathode.

 

Have no fears. This type of question can be answered so quickly and effortlessly. You don't even need to write out the half rxns.

It's asking for the reducing agent which means it gets oxidized. Thus, look for the reactant species that loses electrons (or the thing that will go from neutral to positive, or negative to neutral).

Thus, it has to be Al

 

Remember Cations will go to the Cathode. Cathode = Reduction = Gain of e- (this will go on the left side of the equation)

Al+3 + 3e- ---> Al

Then you have Anions which will go to the Anode. Anode = Oxidation = Loss of e- (this will go on the right side of the equation)

SO4 ----> SO4-2 + 2e-

Somebody please make sure I did this right, I dont want someone to memorize the wrong information lol.

 

Your right but I wouldn't even bring Cathode/Anode in for this type of question. Just know OIL RIG
So you're looking for a compound that was oxidized (loses electrons)

2Al(s) has a zero charge and ends up with a + charge on the products side so it lost electrons AKA got oxidized... and there you go you got your answer

P.S. Whenever the question asks about a reducing/oxidizing agent always change it to oxidized/reduced compound to make it easier and not get mixed up

 

that's what were here for! Good luck!