Question

On the basis of the following $E^0 $ values, the strongest oxidising agent is
$[Fe(CN)_6]^{4-} \rightarrow [Fe(CN)_6]^{3-}+e^-; $
$E^0=-0.35\,V $
$Fe^{2+} \rightarrow Fe^{3+} + e^-;E^0=-0.77 \,V $

• A. $[Fe(CN)_6]^{4-}$
• B. $Fe^{2+} $
• C. $Fe^{3+} $
• D. $[Fe(CN)_6]^{3-} $

Answer 1

Answer: (C)

Substance which have higher reduction potential are stronger oxidising agent.
$[Fe(CN)_6]^{4-}\rightarrow[Fe(CN)_6]^{3-}+e^-, $
$E^0=-0.35 \, V $
$ Fe^{2+}\rightarrow Fe^{3+}+e^-, E^0=-0.77 \, V $
$\because E^0_{oxi}=-E^0_{red} $
$\therefore [Fe(CN)_6]^{3-}+e^- \rightarrow[Fe(CN)_6]^{4-}, E^0=0.35 \, V $
$Fe^{3+}+e^- \rightarrow Fe^{2+} E^0=0.77 \, V $
Hence, $Fe^{3+} $ has maximum tendency to reduced,
so it is the strongest oxidising agent.