# NEET Chemistry Redox Reactions Questions Solved

Standard electrode potential data are useful for understanding the suitability of an oxidant in a redox titration. Some half cell reactions and their standard potential are given below

Mn${\mathrm{O}}_{4}^{-}$(aq) + 8H+(aq) + 5e- $\to$Mn2+(aq) + 4H2O(l);${\mathrm{E}}^{°}$=1051V

Cr2O72-(aq) +14H+(aq) + 6e $\to$2Cr3+(aq) + 7H2O(l);${\mathrm{E}}^{°}$=1.38V

Fe3+(aq) + e- $\to$Fe2+(aq);${\mathrm{E}}^{°}$=0.77V

Cl2(g) + 2e- $\to$2Cl-(aq); ${\mathrm{E}}^{°}$= 1.40V

Identify the only incorrect statement regarding the quantitative estimation of aqueous Fe(NO3)2

1. Mn${\mathrm{O}}_{4}^{-}$ can be used in aqueous HCl

2. Cr2O72- can be used in aqueous HCl

3. Mn${\mathrm{M}}_{4}^{2-}$ can be used in aqueous H2SO4

4.  Cr2O72- can be used in aqueous H2SO4

(1) From reduction electrode potential values,  Mn${\mathrm{O}}_{4}^{-}$ can oxidise Cl- as well as Fe2+. Hence,  Mn${\mathrm{O}}_{4}^{-}$ cannot be used in aqueous HCl for quantitative estimation of Fe(NO3)2.

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