How would you determine the standard electrode potential of the system Mg2+|Mg?
To determine the standard electrode potential of the system Mg2+|Mg, connect it to the standard hydrogen electrode (SHE). Keep the Mg2+|Mg system as cathode and SHE as cathode. This is represented as shown below.
Pt(s) | H2(g, 1 bar)| H+ (aq, 1 M) ||Mg2+ (aq, 1M)| Mg
The electrode potential of a cell is given by
E⊖ = E⊖R – E⊖L
Where,
E⊖R- Potential of the half-cell in the right side of the above representation
E⊖L- Potential of the half-cell in the left side of the above representation
It is to be noted that the potential of the standard hydrogen electrode is zero.
Therefore, E⊖L = 0
E⊖ = E⊖R – 0
⇒ E⊖ = E⊖R