Answer:
-2.372 V
Explanation:
The standard reduction potential is the potential of a cell in which a standard hydrogen electrode (SHE) is one of the half-cells.
The standard potential of a SHE is defined as 0 V.
Mg²⁺(aq) + 2e⁻ ⟶ Mg(s); E° = x V
H₂(g) ⟶ 2H⁺(aq) +2e⁻; E° = 0 V
Mg²⁺(aq) + H₂(g) ⟶ Mg(s) + 2H⁺(aq); E° = -2.372 V
x + 0 = -2.372
x = -2.372
The standard reduction potential of Mg is -2.372 V .