Question

For which of the following electrode reactions the standard electrode potential is the highest at 298 K? The ions are present in aqueous solution. ________.

• A. $Co^{3+}+e^{-}\rightarrow Co^{2+}$
• B. $Cl_{2(g)}+2e^{-}\rightarrow2Cl^{-}$
• C. $MnO_{2(s)}+4H^{+}+2e^{-}\rightarrow Mn^{2+}+2H_{2}O$
• D. $F_{2(g)}+2e^{-}\rightarrow2F^{-}$
• E. $AgCl_{(s)}+e^{-}\rightarrow Ag_{(s)}+Cl^{-}$

Hint:

Fluorine is at the very top of the electrochemical series with the highest reduction potential.

Answer 1

The Correct Option is D

Step 1: Concept
Standard electrode potential ($E^{\circ}$) measures the tendency of a species to be reduced.

Step 2: Meaning
Fluorine ($F_2$) is the most electronegative element and the strongest oxidizing agent in the periodic table.

Step 3: Analysis
The reduction of fluorine gas to fluoride ions has the highest positive reduction potential ($+2.87V$) among all known electrodes.

Step 4: Conclusion
Therefore, the reaction involving $F_2$ has the highest standard electrode potential. Final Answer: (D)