Question

On the basis of standard electrode potential of redox couples given below, find out which of the following is the strongest oxidising agent.
(E$^{\circ}$ values : $Fe^{3+}\left| Fe^{2+}=+ 0.77 V ;
I_{2\left(s\right)}\right|I^{- } =$ $+ 0.54 V; Cu^{2+}\left|Cu= + .34 V ; Ag^{+}\right| Ag = + 0.80 V$)

• A. $Fe^{3+}$
• B. $I_{2(s)}$
• C. $Cu^{2+}$
• D. $Ag^{+}$

Answer 1

Answer: (D)

Higher the electrode potential, better is the oxidising agent. Since, the electrode potential decreases in the order :
$Ag^{+} \left|\,Ag \left(+0.80 \,V\right) \,>\,Fe^{3+}\,\right|\,Fe^{2+}\,\left(+0.77\,V\right)\,>$
$I_{2\left(2\right)}\,\left|\,I^{-}\left(+0.54\,V\right)\,>\,Cu^{2+}\,\right|\,Cu\,\left(+0.34\,V\right)$
Hence, Ag⁺ is the strongest oxidising agent.