Question

Ferrocyanide$\to$Ferricyanide ion$+e^{-}$ $E^o=-0.35V$
Ferrous ion$\to$ Ferric ion $+e^{-}$ $E^o=-0.77V$
Which of the following is strongest oxidant?

• A. Ferrocyanide ion
• B. Ferricyanide ion
• C. Ferrous ion
• D. Ferric ion

Answer 1

Answer: (D)

Ferric ion

Given:

$\left[Fe\right(CN{)}_6{]}^{4-}\to \left[Fe\right(CN{)}_6{]}^{3-}+e^{-}{E}^{\circ }=0.35V$

$F{e}^{2+}\to F{e}^{3+}+e^{-}{E}^{\circ }=-0.77V$

$\mid E^{\circ }\mid$ value is higher for ferrous to ferric conversion. Hence, stronger oxidant, here, will be ferric ion.