cell potential

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Ruiting Jia 4D
Posts: 65
Joined: Fri Sep 28, 2018 12:27 am

cell potential

Postby Ruiting Jia 4D » Sat Mar 16, 2019 9:09 pm

For getting an E(total) from two reactions, how do we know when to add and when to subtract? I always thought we needed to do Ecathode - Eanode ...

Samantha Pacheco 2K
Posts: 60
Joined: Fri Sep 28, 2018 12:29 am

Re: cell potential

Postby Samantha Pacheco 2K » Sat Mar 16, 2019 10:05 pm

If you reverse a half reaction and you do not change sign of E° then we use that equation Ecathode-Eanode, you will always subtract . If you do flip the sign of the E° in the reaction you reversed then you would add the 2 cell potentials.

Karan Thaker 2L
Posts: 75
Joined: Fri Sep 28, 2018 12:26 am

Re: cell potential

Postby Karan Thaker 2L » Sat Mar 16, 2019 10:06 pm

To do E cath - E anode = E cell, always keep the reaction in reduction form... if you reverse anything, you have to add.

eden tefera 2B
Posts: 39
Joined: Fri Sep 28, 2018 12:21 am

Re: cell potential

Postby eden tefera 2B » Sat Mar 16, 2019 10:14 pm

I find it more straightforward to do Ecathode- Eanode rather than reversing Ecell because sometimes the reduction potential is negative and it can get confusing.

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