Page 1 of 1

Favor ability of Cell portential

Posted: Fri Feb 22, 2019 10:37 am
by 005115864
If Cell potential (E) is positive, what does that say about spontaneity and vice versa?

Re: Favor ability of Cell portential

Posted: Fri Feb 22, 2019 11:34 am
by Ethan Baurle 1A
A positive cell potential means spontaneous, a negative cell potential means not spontaneous. Think of the equation Delta G = -nFE. Negative delta G is spontaneous, and n (electrons transferred) and F (Faraday's constant) are always positive. Thus the, the sign of E (cell potential) determines whether or not the reaction is spontaneous.

Re: Favor ability of Cell portential

Posted: Fri Feb 22, 2019 12:21 pm
by Deepika Pugalenthi 1A
When cell potential is positive, it indicates a spontaneous reaction because Gibbs free energy is negative. This is due to the equation for work done, or work max (work max = -charge x E). When incorporating Faraday into the equation, work max = -nFE.

Work max equals Gibbs free energy due to the redox reaction occurring under constant temperature and pressure. In order for the reaction to be spontaneous, cell potential must be positive in order to obtain an overall negative value. A reaction is spontaneous when Gibbs free energy is negative.

Re: Favor ability of Cell portential

Posted: Fri Feb 22, 2019 12:41 pm
by Lorena Zhang 4E
Technically, if the galvanic cell is running properly and measured correctly, the cell potential should always be positive. This also means that the reaction would be spontaneous according to the equation since delta G would be negative.

Re: Favor ability of Cell portential

Posted: Sat Feb 23, 2019 1:45 am
by Nicholas Le 4H
A positive cell potential means that the reaction is spontaneous, while a negative cell potential means that the reaction is not spontaneous.

Re: Favor ability of Cell portential

Posted: Sat Feb 23, 2019 11:11 am
by MadelynNguyen1F
If the cell potential is negative, does that also mean that the reverse reaction is spontaneous?