JEE Main 2017ChemistryElectrochemistryMediumMCQ

JEE Main 2017 — Electrochemistry Question with Solution

JEE Main 2017 (08 Apr Online)

Question

What is the standard reduction potential Eo for Fe3+→Fe?

Given that:

Fe2++2e-→Fe;EFe2+/Feo=-0.47V

Fe3++e-→Fe2+;EFe3+/Fe2+o=+0.77V

Choose an option

Show full solutionCorrect option: A
Correct answer
A-0.057 V

Step-by-step explanation

i Fe3+→Fe  E1o;

'n' factor=3

ΔG1∘=−3 ×F×E1o

ii Fe3++e−→Fe2+E2o; 0.77

'n' factor=1

∆G2∘=-1×F×0.77

iii Fe2++2e−→Fe E3o=-0.47 

'n' factor=2

∆G3∘=-2×F×-0.47

ΔG1=ΔG2+ΔG3

−3FE1o = −1×0.77×F+2×0.47×F

-E1o=2×0.47+-0.77F3F=0.057 V

E1o=- 0.057 V

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About this question

This is a previous-year question from JEE Main 2017, covering the Electrochemistry chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.