Standard electrode potentil data are useful for understanding the suitability of an oxidant in a red

Question

Standard electrode potentil data are useful for understanding the suitability of an oxidant in a redox titration. Some half-cell reaction and their standard potentials are give below :
MnO₄^- (aq) + 8H⁺ (aq) + 5e^- → Mn²⁺(aq) + 4H₂O(l), E^o = 1.51V
Cr₂O₇^2- (aq) + 14H⁺ (aq) + 6e^- → 2Cr³⁺ (aq) + 4H₂O(l), E^o = 1.38V
Fe³⁺(aq) + e^- → Fe²⁺(aq) E^o = 0.77V
Cl₂(g) + 2g^- → Cl^- (aq) E^o = 1.40V
Identify the incorrect statement regarding the quantitative estimation of aqueous Fe (NO₃)₂ :

Accepted Answer

MnCO4- will oxidise Cl- ion according to equation. Mn7+ + 5e &#8594; Mn2+ 2Cl- &#8594; Cl2 + 2e Thus Eocell = EoO.P.Cl-/Cl2 + EoR.P.Mn7+/Mn2+ = - 1.40 + 1.51 = 0.11V or reaction is feasible. MnO4- will oxidise Fe2+ to Fe3+ Fe2+ &#8594; Fe3+ + e Eocell = EoO.P.Fe2+/Fe3+ + EoR.P.Mn2+/Mn2+ = - 0.77 + 1.51 = 0.74V or reaction is feasible. Thus MnO4- will not oxidise only Fe2+ to Fe3+ in aqueous HCl but it will also oxidise Cl- to Cl2. Suitable oxidant should not oxidise Cl- to Cl2 and should oxidise only Fe2+ to Fe3+ in redox titration.

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