Determine Cathode and Anode

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Michelle_Nguyen_3F
Posts: 40
Joined: Wed Sep 21, 2016 2:59 pm

Determine Cathode and Anode

Postby Michelle_Nguyen_3F » Tue Feb 14, 2017 11:16 pm

Hello!

I just wanted to make sure my reasoning is correct: If both of the half reactions are written as a reduction reactions, then the one with the higher reduction potential is more likely to be reduced, and is therefore the oxidizing agent and the cathode. The one with the lower reduction potential is less likely to be reduced and is therefore oxidized, and is the reducing agent and the cathode. Is this correct? Also, when finding Enot of a galvanic cell, we always want this value to be as positive or as big as possible, and so we would chose which half reaction to flip and make the anode based on which "combination" of half-reactions will give us the most positive value? Thank you!!

Liam Giffin 2B
Posts: 34
Joined: Fri Jul 22, 2016 3:00 am
Been upvoted: 1 time

Re: Determine Cathode and Anode

Postby Liam Giffin 2B » Tue Feb 14, 2017 11:37 pm

This is mostly correct, because you want your cell potential to be positive, which will only occur if the reaction with the greater reduction potential occurs at the cathode and the reaction with the smaller reaction potential occurs at the anode. The only thing you said that I believe is incorrect is that the reducing agent is the cathode, the reducing agent is actually the thing that is oxidized, so it is the anode.

Amber Duong 1B
Posts: 10
Joined: Wed Sep 21, 2016 2:55 pm

Re: Determine Cathode and Anode

Postby Amber Duong 1B » Wed Feb 15, 2017 4:44 pm

The strongest oxidizing agent is the one with the most positive reduction potential. Also this will be the electrode that is reduced in the cathode. On the other hand, the weakest oxidizing agent or strongest reducing agent is the one with the most negative reduction potential, and it will be oxidized in the anode.


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