1.

Given, standard electrode potentials `Fe^(2+) +2e^(-) rarr Fe, E^(@)=-0.440 V` `Fe^(3+)+3e^(-) rarr Fe, E^(@)=- 0.036 V` The standarde potential `(E^(@))` for `Fe^(2+)+e^(-) rarr Fe^(2+)`, isA. `+0.772 V`B. `-0.772 V`C. `+0.417 V`D. `-0.417 V`

Answer» Correct Answer - A
`Fe^(2+)+2e^(-) rarr Fe, DeltaG^(@)=-nFE^(@)` …(i)
`DeltaG^(@)=-2xxFxx(-0.440V)=0.880 F`
`Fe^(3+)+3e^(-) rarr Fe` …(ii)
`DeltaG^(@)=-3xxFxx(-0.036)`
`=0.108 F`
On subtracting Eq. (ii) from Eq. (i) we get
`Fe^(3+) +e^(-) rarr Fe^(2+)`
`DeltaG^(@)=0.108 F-0.880 F=-0.772 F`
`E^(@)=(-DeltaG^(@))/(nF)=((-0.772 F))/(1xxF)= +0.772 V`


Discussion

No Comment Found

Related InterviewSolutions