Potential of Ag/Ag+ electrode

[Chris-jap]

Hello everybody

I would like to know the potential of two electrode.

1- The first is the electrode of Ag/Ag+ in a saturated solution of NaCl

I think that the pKs of AgCL is 9.8 (is it right?)
So
E= E0+0.06log[(Ks)1/2]
E=0.8-0.506
E=0.506 vs ENH

Is it correct? (in a book I found a value of 0.2 so...)

2- The second is the electrode of Ag/Ag+ in a solution of NaCl at 3 mol/L this time
so
E=E0+0.06logKs-0.06log[Cl+] ??
E=0.8-0.588-0.0286=0.183 V vs ENH
Is it correct?

Thank you for your help
Chris

 

[siddharth]

Hello everybody

I would like to know the potential of two electrode.

1- The first is the electrode of Ag/Ag+ in a saturated solution of NaCl

I think that the pKs of AgCL is 9.8 (is it right?)
So
E= E0+0.06log[(Ks)1/2]
E=0.8-0.506
E=0.506 vs ENH

Is it correct? (in a book I found a value of 0.2 so...)

The Ksp is 1.8*10^-10, so the pKs comes to around 9.745.

Everything seems right, till "E=0.8-0.506". Shouldn't it be 0.588, as you used in the next question? If you do that, you get E = 0.8-0.588
= 0.212

2- The second is the electrode of Ag/Ag+ in a solution of NaCl at 3 mol/L this time
so
E=E0+0.06logKs-0.06log[Cl+] ??
E=0.8-0.588-0.0286=0.183 V vs ENH
Is it correct?

This appears correct (ofcourse, Cl^-).

 

[Blueshift5]

Hello Chris, thank you for your inquiry about the potential of the Ag/Ag+ electrode. The potential of this electrode can vary depending on the conditions of the solution it is in, such as the concentration of NaCl and the presence of other ions. However, your calculations seem to be on the right track.

1. The potential of the Ag/Ag+ electrode in a saturated solution of NaCl can be calculated using the Nernst equation: E = E0 + 0.0592 log [Ag+] / [AgCl]. The pKs of AgCl is indeed 9.8, but the value you have used for the standard potential (E0) is incorrect. The standard potential for the Ag/Ag+ electrode is 0.799 V vs SHE (standard hydrogen electrode), not 0.8 V. Using this correct value, the potential for the Ag/Ag+ electrode in a saturated solution of NaCl would be 0.197 V vs SHE.

2. For the electrode in a 3 mol/L NaCl solution, your calculation is again close but there are a few corrections. The Nernst equation for this scenario would be: E = E0 + 0.0592 log [Ag+] / [AgCl] - 0.0592 log [Cl-]. Using the same standard potential of 0.799 V, the potential for this electrode would be 0.210 V vs SHE. Please note that the [Cl-] concentration should be in molar units, not mol/L.

I hope this helps clarify the potential of the Ag/Ag+ electrode in these two scenarios. Keep in mind that these calculations are based on ideal conditions and in practice, there may be some variations due to other factors. It is always important to consider the experimental conditions and any potential interferences when using this electrode. Thank you for your interest in this topic.