flipping the sign of Ecell


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Saachi_Kotia_4E
Posts: 68
Joined: Fri Sep 28, 2018 12:23 am

flipping the sign of Ecell

Postby Saachi_Kotia_4E » Wed Feb 27, 2019 9:50 am

if the E cell for a half reaction in Appendix 2B has a positive value, but the half reaction used in the problem is the other way around, do we flip that value of Ecell?

mcredi
Posts: 63
Joined: Fri Sep 28, 2018 12:16 am

Re: flipping the sign of Ecell

Postby mcredi » Wed Feb 27, 2019 10:07 am

yes, when the reaction is reversed you flip the sign

Hedi Zappacosta 1E
Posts: 66
Joined: Fri Sep 28, 2018 12:27 am

Re: flipping the sign of Ecell

Postby Hedi Zappacosta 1E » Wed Feb 27, 2019 10:41 am

This is because E cell is the reduction potential. If you are looking at an oxidation reaction, you have to flip the sign of the reduction potential

Alexa Tabakian 1A
Posts: 38
Joined: Fri Sep 28, 2018 12:20 am

Re: flipping the sign of Ecell

Postby Alexa Tabakian 1A » Wed Feb 27, 2019 1:23 pm

All E cell values are reduction values. You can either flip the sign for oxidation or use the formula Ecell= Eright-Eleft

Mona El Masri 1F
Posts: 34
Joined: Fri Sep 28, 2018 12:20 am

Re: flipping the sign of Ecell

Postby Mona El Masri 1F » Wed Feb 27, 2019 1:24 pm

You don't do anything to the sign of E if you decide to use (cathode-anode).

Arta Kasaeian 2C
Posts: 30
Joined: Mon Jan 07, 2019 8:22 am

Re: flipping the sign of Ecell

Postby Arta Kasaeian 2C » Wed Feb 27, 2019 3:27 pm

Yes, if needed to change calculate oxidation potential, you must switch the sign of the reduction potential.


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