cell potential

Moderators: Chem_Mod, Chem_Admin

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.

Return to “Work, Gibbs Free Energy, Cell (Redox) Potentials”

Who is online

Users browsing this forum: No registered users and 1 guest