Question

How to calculate standard reduction potential experimentally?

Answer 1

As far as I understand, standard potential can be calculated from free Gibbs energy of a reaction. Thus, for CO2 reduction in aqueous electrolytes:

CO2 + 2H+ + 2e- -> CO + 2 H2O, E0=-0.52 V NHE (pH=7)

(literature value). Then, using Nernst equation, you can calculate E0 for the concntrations in your system.

But for acetonitrile solution, E0 might be different: either above reaction, or its free energy may not be the same.

hope it clears your doubt dear