Question

On the basis of the following `E^(@)` values, the stongest oxidizing agent is `[Fe(CN)_(6)]^(4-) rarr [Fe(CN)_(6)]^(3-)+e^(-), E^(@) = -0.35 V`
`Fe^(2+) rarr Fe^(3+)+e^(-), E^(@) = -0.77 V`
A. `[Fe(CN)_(6)]^(4-)`
B. `Fe^(2+)`
C. `Fe^(3+)`
D. `[Fe(CN)_(6)]^(2-)`

Answer 1

Correct Answer - C
Oxidizing agent oxidizes the other substance and gets reduced. Thus, higher the reduction potential, stronger the reducing agent:
`[Fe(CN)_(6)]^(3-)+e^(-) rarr [Fe(CN)_(6)]^(4-),, E^(@) = 0.35 V`
`Fe^(3+)+e^(-) rarr Fe^(2+),, E^(@) = 0.77 V`
Since `E_(Fe^(3+)//Fe^(2+))^(@)gt E_([F^e(CN)_(6)]^(3-)//[Fe(CN)_(6)]^(4-)), Fe^(3+)` is the strongest oxidizing agent.