Nernst equation... missing info?

[ecoli]

For my chem lab, we have to do calculations based off Nerns's law.

 

[math] E = E^{0} - \frac{RT}{F}ln [H^{+}] [/math]

 

The question...

From the Nernst equation as it applies to the pH electrode, calculate the difference in pH corresponding to a difference in voltage of 0.1 mV (0.0001 V) at 20 C

 

Isn't this question missing information? such as E, since you need to solve for ln [H+]... am I right?

[tash =)]

I'm guessing, but wouldn't E be 0.1mV and E0 be zero?

[LazerFazer]

Couldn't it be re-arranged to read:

 

[math]

E - E^{0} = - \frac{RT}{F}ln [H^{+}]

[/math]

 

and since

 

[math]

\Delta E = E - E^{0} = 0.1mV

[/math]

 

you should be able to solve it.

 

cheers,

LF

[ecoli]

Couldn't it be re-arranged to read:

 

[math]

E - E^{0} = - \frac{RT}{F}ln [H^{+}]

[/math]

 

and since

 

[math]

\Delta E = E - E^{0} = 0.1mV

[/math]

 

you should be able to solve it.

 

cheers' date='

LF[/quote']

 

yeah, that's it. I kinda figured that out after I posted this question, but thanks for the help anyways. The problem was, the lab that I got this equation from wasn't very clear on defining the variables. Thanks guys.