## Question regarding: "E° + Value means reduction is spontaneous"

Suk Jin Song 3L
Posts: 11
Joined: Tue Nov 17, 2015 3:00 am

### Question regarding: "E° + Value means reduction is spontaneous"

Hello, just a quick question on what "E° + Value means reduction is spontaneous" means. It's on page 46 of the course reader.

What do they mean by "value" and is there a case when E° is not spontaneous?

Thomas_Rodriguez_3G
Posts: 12
Joined: Wed Sep 21, 2016 2:58 pm

### Re: Question regarding: "E° + Value means reduction is spontaneous"

I think its "E positive value," not E plus value.

Kristen Hazama 1I
Posts: 10
Joined: Wed Nov 18, 2015 3:00 am

### Re: Question regarding: "E° + Value means reduction is spontaneous"

E° must always be positive or else the reaction will not occur. The value comes from the equation E°cell=E°cathode - E°anode. If E° were negative, the reaction would be non-spontaneous because the work would not be done by the system. On page 49, there is the equation deltaG°=-nFE°. If E°were negative then you would be multiplying a negative by a negative, making deltaG° positive, which means the reaction is non-spontaneous. Therefore, E° must always be positive.

DBaquero
Posts: 13
Joined: Wed Sep 21, 2016 2:59 pm
Been upvoted: 1 time

### Re: Question regarding: "E° + Value means reduction is spontaneous"

Yeah if E°is negative then it would require outside energy in order for the reaction to occur.