# Electrochemistry Reference Electrodes

1. Sep 3, 2013

### war485

1. The problem statement, all variables and given/known data

Change your electric potential readings from a Ag/AgCl system to a RHE (reversible hydrogen electrode) system at pH 7.

For example, 0.3 V vs Ag/AgCl and -0.1 V vs Ag/AgCl

2. Relevant equations

Ag/AgCl 0.222 Volts
RHE 0 - 0.0591*pH Volts

3. The attempt at a solution

RHE at pH 7 = 0.4137 V

0.3 V vs Ag/AgCl + (0.197 - 0.4137) = 0.08333 V ?
-0.1 V vs Ag/AgCl + (0.197 - 0.4137) = -0.3167 V ?

2. Sep 5, 2013

### Staff: Mentor

-0.0591*7 is not 0.4137

Not that I am sure about the correct signs, but what you did looks inconsistent.

3. Sep 5, 2013

### war485

ah yes I forgot to put that negative sign on my post. So RHE at pH 7 = 0.4137 V should really be read as RHE at pH 7 = -0.4137 V
everything below that assumed that sign was there in the first place.

Are my signs or thinking inconsistent? I was trying to think of everything in terms of SHE (standard hydrogen electrode), which is marked as 0 V.

4. Sep 5, 2013

### Staff: Mentor

What is 0.197?

Edit: I mean, I know what it is, I wonder why you used 0.197 on calculations, but you listed 0.222 earlier.

5. Sep 5, 2013

### war485

I was given 0.222 V.
0.197 V would be for a saturated chloride solution, ooh, oups, that belongs to a followup problem (not relevant to this thread), I see what you mean now. It should say 0.222 V not 0.197 V