Nernst


Moderators: Chem_Mod, Chem_Admin

Zoya Mulji 1K
Posts: 105
Joined: Thu Jul 11, 2019 12:15 am

Nernst

Postby Zoya Mulji 1K » Sun Feb 23, 2020 9:40 pm

What do all of the variables in the Nernst equation mean?

Naji Sarsam 1F
Posts: 104
Joined: Sat Aug 17, 2019 12:18 am

Re: Nernst

Postby Naji Sarsam 1F » Sun Feb 23, 2020 9:48 pm

The Nernst is

E is the cell potential of a reaction not at equilibrium and not at standard conditions
is the cell potential at standard conditions
R is the gas constant
T is the temperature of the reaction
n is the moles reacting
F is faradays constant
Q is the reaction quotient, meaning the same proportion as k but when the reaction is not at equilibrium

Tracy Tolentino_2E
Posts: 140
Joined: Sat Sep 07, 2019 12:17 am

Re: Nernst

Postby Tracy Tolentino_2E » Sun Feb 23, 2020 9:51 pm

In the Nernst equation, E = E(not) - (RT/nF)lnQ.
E(not) is the standard cell potential
R is the gas constant (8.314 J/K mol)
T is temperature (in Kelvin)
n is the moles of electrons transferred
F is Faraday's constant . (96485 C/mol)
Q is the concentration of products over concentration of reactants

DesireBrown1J
Posts: 98
Joined: Wed Sep 18, 2019 12:18 am

Re: Nernst

Postby DesireBrown1J » Sun Feb 23, 2020 10:21 pm

Why is n moles of electrons transferred instead of the number of electrons transferred? How do we convert it into moles if they are electrons?

Ashley Fang 2G
Posts: 102
Joined: Fri Aug 30, 2019 12:17 am

Re: Nernst

Postby Ashley Fang 2G » Mon Feb 24, 2020 10:26 am

The n comes from the equation ΔG = -nFE which is used to derive the nernst equation.
Since F is in units of C/mole, multiplying that by n (moles) would cancel out the units.

GFolk_1D
Posts: 101
Joined: Fri Aug 09, 2019 12:15 am

Re: Nernst

Postby GFolk_1D » Mon Feb 24, 2020 10:33 am

When exactly is the cell potential considered at standard conditions?

805097738
Posts: 180
Joined: Wed Sep 18, 2019 12:20 am

Re: Nernst

Postby 805097738 » Mon Feb 24, 2020 4:07 pm

DesireBrown1J wrote:Why is n moles of electrons transferred instead of the number of electrons transferred? How do we convert it into moles if they are electrons?


They are the same. The number of electrons is the moles of electrons.

Bilal Pandit 1J
Posts: 98
Joined: Wed Sep 11, 2019 12:16 am

Re: Nernst

Postby Bilal Pandit 1J » Mon Feb 24, 2020 4:47 pm

If you figure out the reduction equation and the oxidation reaction, and when you cancel them out you will see the exact number of electrons being transferred, which will be your n.


Return to “Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)”

Who is online

Users browsing this forum: No registered users and 2 guests