Value of n


Moderators: Chem_Mod, Chem_Admin

Henry Krasner 1C
Posts: 64
Joined: Fri Sep 28, 2018 12:15 am

Value of n

Postby Henry Krasner 1C » Tue Feb 26, 2019 11:47 am

Is n the difference in the number of moles on each side, or the number of electrons on each side of an equation?

Mindy Kim 4C
Posts: 65
Joined: Fri Sep 28, 2018 12:25 am

Re: Value of n

Postby Mindy Kim 4C » Tue Feb 26, 2019 11:50 am

n represents how many electrons are being transferred in the reaction. The value should be the same whether you are looking at the oxidation or reduction half reactions as the number of electrons should be the same if the half reactions are balanced.

Danny Elias Dis 1E
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

Re: Value of n

Postby Danny Elias Dis 1E » Wed Feb 27, 2019 10:33 am

It is important to keep in mind that n as the number of electrons only applies to the equation deltaG = -nFE, deltaG° = -nFE°, or Wmax = -nFE (these are the only equations from class). When using n in other equation such as the ideal gas law (PV = nRT), n is the number of moles.

beckyolmedo1G
Posts: 34
Joined: Fri Sep 28, 2018 12:21 am

Re: Value of n

Postby beckyolmedo1G » Wed Feb 27, 2019 10:45 am

In order to find n (the number of electrons transferred) write down both half reactions and balance them. You always want to make sure that the number of electrons being transferred is the same amount for both half reactions.

Jasmine Chow 1F
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am
Been upvoted: 1 time

Re: Value of n

Postby Jasmine Chow 1F » Wed Feb 27, 2019 7:09 pm

Once the redox reaction is balanced you should have an equal number of electrons on both sides of the equation. That will be the n value. There can only be one value for n. If you think you have two then you did not balance your redox equations correctly.

Nina Do 4L
Posts: 61
Joined: Fri Sep 28, 2018 12:27 am

Re: Value of n

Postby Nina Do 4L » Wed Feb 27, 2019 7:13 pm

After you create your two half reactions, you need to balance the amount of electrons in order to combine the reaction into one. In the process of balancing out the amount of electrons, you find your number of moles of electrons. It is the number of e- you used to balance the reaction.

Angela Cong 3C
Posts: 69
Joined: Fri Sep 28, 2018 12:25 am

Re: Value of n

Postby Angela Cong 3C » Wed Feb 27, 2019 9:45 pm

Sometimes there are cases where you simplify the balanced redox reaction, would n be the number of moles before simplification or would it be the number of moles after simplification?

Jeannine 1I
Posts: 73
Joined: Fri Sep 28, 2018 12:27 am

Re: Value of n

Postby Jeannine 1I » Thu Feb 28, 2019 5:14 pm

Angela Cong 3C wrote:Sometimes there are cases where you simplify the balanced redox reaction, would n be the number of moles before simplification or would it be the number of moles after simplification?


In a redox reaction, you would look at the half-reactions you used to cancel out the electrons before you formed the balanced redox reaction. The cancelled out electrons are the number of electrons transferred, and so that would be the value n!


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

Who is online

Users browsing this forum: No registered users and 2 guests