Solution: As the reduction potential is reduced, the reducing power increases proportionally. The following are the standard electrode potentials in ascending order (increasing order): K⁺/K < Mg²⁺/Mg < Cr³⁺/Cr < Hg²⁺/Hg < Ag⁺/Ag

Therefore, in the order of reducing power, we can arrange the given metals as Ag< Hg < Cr < Mg < K