Chemistry - Redox Reactions Question with Solution | TestHub

The skeletal reactions are

$\begin{array}{ccc}{\text{BaCrO}}_4+\text{HCl}& ⟶& {\text{Cr}}_2{\text{O}}_7^{2-}+{\text{Ba}}^{2+}\\ {\text{Cr}}_2{\text{O}}_7^{2-}+{\text{I}}^{-}& ⟶& {\text{Cr}}^{3+}+{\text{I}}_3^{-}\\ {\text{I}}_3^{-1}+{\text{S}}_2{\text{O}}_3^{2-}& ⟶& {\text{S}}_4{\text{O}}_6^{2-}+{\text{I}}^{-}\end{array}$

Meqs of Na₂S₂O₃= 21 x 0.095 x 1 = 1.995 Meqs of${\text{I}}_3^{-}$

$\equiv$Meqs of${\text{Cr}}_2{\text{O}}_7^{2-}$

mM of${\text{Cr}}_2{\text{O}}_7^{2-}=\frac{1\text{.}995}{6}$

mM of$\text{Cr}{\text{O}}_4^{2-}=\frac{1\text{.}995}{6}\times 2=0\text{.}665$mM of BaCrO₄

Mass % of BaCl₂. 2H₂O$=\frac{0\text{.}665\times 10^{-3}\times 244}{0\text{.}230}\times 100=70\text{.}5\text{\%}$