Given the standard electrode potentials, K⁺/K = -2.93V, Ag⁺/Ag = 0.80V, Hg²⁺/Hg = 0.79V, Mg²⁺/Mg = -2.37V, Cr³⁺/Cr = -0.74V arrange these metals in their increasing order of reducing power.
Ag < Hg < Cr < Mg < K
Explanation
The reducing power of a metal is inversely proportional to its standard electrode potential. A lower (more negative) standard electrode potential indicates a higher tendency to lose electrons, making the metal a stronger reducing agent. The given potentials are Ag⁺/Ag = 0.80V, Hg²⁺/Hg = 0.79V, Cr³⁺/Cr = -0.74V, Mg²⁺/Mg = -2.37V, and K⁺/K = -2.93V. Arranging these in decreasing order of their electrode potentials gives the increasing order of their reducing power.
Solution Steps
Step 1: Understand the relationship between standard electrode potential and reducing power. A lower reduction potential means a greater capability to lose electrons, hence a stronger reducing agent.
Step 2: List the given metals with their standard electrode potentials: Ag = V, Hg = V, Cr = V, Mg = V, K = V.
Step 3: Arrange the metals in decreasing order of their electrode potentials: Ag (V) > Hg (V) > Cr (V) > Mg (V) > K (V).
Step 4: Reverse this order to get the increasing order of reducing power: Ag < Hg < Cr < Mg < K.