### Midterm 2012 Q: 7A

Posted:

**Sun Feb 07, 2016 6:43 pm**How do you get -0.35? I got -2.02 for my answer

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=141&t=11780

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Posted: **Sun Feb 07, 2016 6:43 pm**

How do you get -0.35? I got -2.02 for my answer

Posted: **Sun Feb 07, 2016 7:23 pm**

I'm not quite understanding how you're getting -2.02 with those values. You're given Ecell=-0.689 and Eanode=0.34

The equation you will use is Ecell=Ecathode-Eanode, where you want to find the value of Ecathode.

Rearrange the equation to solve for Ecathode:

Ecathode=Ecell+Eanode

So, plugging in the numbers for Ecell and Eanode:

(Ecathode)=(-0.689v)+(0.34v)

Ecathode=-0.35

The equation you will use is Ecell=Ecathode-Eanode, where you want to find the value of Ecathode.

Rearrange the equation to solve for Ecathode:

Ecathode=Ecell+Eanode

So, plugging in the numbers for Ecell and Eanode:

(Ecathode)=(-0.689v)+(0.34v)

Ecathode=-0.35

Posted: **Sun Feb 07, 2016 7:55 pm**

I was dividing 0.689 by 0.34, I get it now. Thanks!