Redox Reactions And Electrochemistry Ques 341
Question: Given standard electrode potentials: $ F{e^{3+}}+3{e^{-}}\to Fe; $ $ E^{o}=-,0.036volt $ $ F{e^{2+}}+2{e^{-}}\to Fe; $ $ E^{o}~=-,0.440volt $ The standard electrode potential $ E{}^\circ $ for $ F{e^{3+}}+{e^{-}}\to F{e^{2+}} $
Options:
A) $ -,0.476 $ volt
B) $ -,0.404 $ volt
C) 0.440 volt
D) 0.772 volt
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ F{e^{3+}}3e\to Fe, $ $ E^o_1=-0.036,volt;\Delta G^o_1 $ $ Fe\to F{e^{2+}}+2{e^{-}}, $ $ E^o_2=0.44,volt;\Delta G^o_2 $ $ F{e^{3+}}+{e^{-}}\to \Delta G^{o}=\Delta G^o_1+\Delta G^o_2 $ $ -nFE^{0}=-FE^0_1+(-2FE^0_2) $
$ \Rightarrow -FE^{0}=-F(3E^0_1+2E^0_2) $ $ E^{o}=(3\times (0.036)+(2\times 0.44) $ $ E^{o}=0.772volt $
