A 2 . 0   g sample containing MnO 2 is treated with HCl liberating Cl 2 . The Cl 2 gas is passed into a…

${\mathrm{MnO}}_2+4\mathrm{HCl}⟶{\mathrm{MnCl}}_2+{\mathrm{Cl}}_2\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}$

${\mathrm{Cl}}_2+2\mathrm{Kl}⟶{\mathrm{I}}_2+2\mathrm{KCl}$

${\mathrm{I}}_2+2{\mathrm{Na}}_2{ \mathrm{S}}_2{\mathrm{O}}_3⟶2\mathrm{Nal}+{\mathrm{Na}}_2{ \mathrm{S}}_4{\mathrm{O}}_6$

Mili eq. of ${\mathrm{MnO}}_2=$ Mili eq. of ${\mathrm{Cl}}_2=$ Mili eq. of ${\mathrm{I}}_2=$ Mili eq. of Hypo.

$2\left(\frac{\mathrm{w}}{87}\right)=\left[0.1\times 60\right]$

$\mathrm{W}=261$ miligram

$\% \mathrm{of} {\mathrm{MnO}}_2=\frac{0.261}{2}\times 100=13.05\%\approx 13$