Question

Convert potentials

0.523 V vs. S.H.E = _______ V vs. Ag/AgCl

0.023 V vs. S.C.E= ________V vs. Ag/AgCl

Answer 1

1. Given, 0.523 V vs SHE (Standard Hydrogen Electrode, E_SHE=0.0 V).

E_relative = E_real - E_ref => 0.523 V = E_real -0.0 V => E_real = 0.523 V

This means that the real EMF is 0.523 V. Now, we have to convert it with relative to Ag|AgCl reference electrode.

We know that the electron potential Ag|AgCl reference electrode is 0.197.

E_relative= E_real - E_ref = 0.523 - 0.197 = 0.326 V

Hence, 0.523 V vs. S.H.E = 0.326 V vs. Ag/AgCl

2. Given, 0.023 V vs S.C.E. (Standard Calomel Electron, E_SCE=0.241 V). This time the real potential is

E_relative = E_real - E_ref

0.023 = E_real -0.241

E_real = 0.264 V

Now, we have to convert this relative to Ag/AgCl electrode.

E_relative = E_real - E_ref

=0.264 - 0.197 = 0.067 V

Hence, 0.023 V vs. S.C.E= 0.067 V vs. Ag/AgCl