Standard electrode potentials are
`Fe^(2+)//Fe, E^(@) = -0.44 V`
`Fe^(3+)//Fe^(2+), E^(@) = +0.77 V`
If `Fe^(3+), Fe^(2+)`, and Fe block are kept together, then

Options

A. `Fe^(3+)` increases
B. `Fe^(3+)` decreases
C. `Fe^(2+)//Fe^(3+)` remains unchanged
D. `Fe^(2+)` decreases.

Answer

B

Explanation

As `E(Fe^(3+)//Fe^(2+))` is more than
` E(Fe^(2+)//Fe),therefore Fe^(3+)` will get reduced and Fe will get oxidsied As such `Fe^(3+)` will decrease.