Question

Given the standard electrode potentials K⁺/K = -2.93 V; Ag⁺/Ag = 0.80 V; Mg₂²⁺/Hg = 0.79; Mg²⁺/Mg = -2.37 V; Cr²⁺/Cr = -0.74 V.

Arrange these metals in their increasing order of reducing power.

(a) Ag < Hg < Cr < Mg < K
(b) K < Mg < Cr < Hg < Ag
(c) Hg < Cr < Mg < K < Ag
(d) Mg < Cr < Hg < Ag < K

Answer 1

(a) Ag < Hg < Cr < Mg < K

Lower the reduction potential, more easily it is oxidized and hence greater is its reducing power.