Question

Given the standard electrode potentials,

K⁺/K = −2.93 V, Ag⁺/Ag = 0.80 V,

Hg²⁺/Hg = 0.79 V

Mg²⁺/Mg = −2.37 V, Cr³⁺/Cr = −0.74 V

Arrange these metals in their increasing order of reducing power.

Answer 1

A metal’s oxidation potential determines its reducing power. Its tendency to be oxidised and, thus, its reducing power increase with its oxidation potential. Therefore, the following will be the order in which the power of the specified metals increases or decreases:

Ag < Hg < Cr < Mg < K