Calculating n in the Nernst Equation

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Liz White 1K
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Joined: Thu Jul 13, 2017 3:00 am

Calculating n in the Nernst Equation

Postby Liz White 1K » Sat Feb 24, 2018 7:41 pm

I have a question about the variable n in the Nernst Equation. I have read that it correlates to the number of electrons transferred across the reaction. However, how is this calculated when there are 3 electrons added on the reactants side of the equation and two added to the products side? Do you do products minus reactants, or add them together for an overall total, or something else? Someone please explain!

Shawn Patel 1I
Posts: 54
Joined: Thu Jul 27, 2017 3:01 am

Re: Calculating n in the Nernst Equation

Postby Shawn Patel 1I » Sat Feb 24, 2018 7:52 pm

When trying to find n in the nerst equation, and there is an uneven amount of electrons on each side, you usually have to balance out the equations so that the electrons cancel. The final amount of electrons after you balance is what you use for n.

Christine Wastila 1H
Posts: 61
Joined: Fri Sep 29, 2017 7:04 am

Re: Calculating n in the Nernst Equation

Postby Christine Wastila 1H » Sat Feb 24, 2018 7:58 pm

Since you have different amounts of electrons being transferred, you want to find the least common multiple of those two coefficients. In the case of 3 and 2, the least common multiple is 6. So multiply the reaction with 3 electrons on the reactant side by 2 and multiply the reaction with 2 electrons on the products side by 3 that way there are 6 on each side, which will then cancel out. Since 6 was the least common multiple, it will also be your n value.

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