The equilibrium constant of the following redox rection at 298 K is `1 xx 10^(8)`
`2Fe^(3+) (aq.) +2I^(-) (aq.) hArr 2Fe^(2+)(aq.) +I_(2) (s)`
If the standard reducing potential of iodine becoming iodide is +0.54 V. what is the standard reduction potential of `Fe^(3+)//Fe^(2+)` ?

Options

A. `64.2`
B. `51.0`
C. `48.4`
D. `25.5`

Answer

B

Explanation

No. of equivalent of copper (II) salt =
No. of equivalent of Iodine =No. of equivalents of hypo
`rArr` No. of equivalent of copper (II) salt `= 24.5 xx 0.1 = 2.45`
No. of milli moles of copper (II) salt `=2.45`
Weight of copper in copper (II) salt
`=2.45 xx 63.5 xx 10^(-3) = 0.1556g`
`0.305g` of copper (II) salt contain `=0.1556g` of Cu
`:. %` copper `=(0.1556)/(0.305) xx 100 = 51%`