Question

The standard reduction electrode potential of four elements A, B, C and D are $0.8\mathrm{V},0.2\mathrm{V},–1.8\mathrm{V}$ and $–0.5\mathrm{V}$ respectively, the element with the highest reducing power is

• A. A
• B. B
• C. C
• D. D

Answer 1

The correct option is C

C

Explanation for correct answer:

Option (c) C

Standard electrode potential:

• The standard electrode potential is a determination of the equilibrium potential.
• The potential of the electrode is the difference in potential between the electrode and the electrolyte.
• When the concentrations of all the species in a semi-cell are equal, the electrode potential is referred to as the standard electrode potential.
• A solution with a greater (more positive) reduction potential than the new species will tend to receive electrons from the new species (i.e., to be reduced by oxidizing the new species) and a solution with a lower (more negative) reduction potential will tend to lose electrons to the new species.
• The more negative the standard reduction potential, the stronger the reducing agent in other words Reducing power is inversely related to reduction potential.
• So, if the standard reduction electrode potential of four elements A, B, C and D are $0.8\mathrm{V},0.2\mathrm{V},–1.8\mathrm{V}$ and $–0.5\mathrm{V}$ respectively, the element with the highest reducing power is $\mathrm{C}>\mathrm{D}>\mathrm{B}>\mathrm{A}$

Thus, the correct option is (c).