A 2.0 g sample containing MnO_2 is treated with HCl liberating Cl_2. The Cl_2 gas is passed into a solution of KI and 60.0 mL of 0.1 M Na_2 S_2 O_3…

A $\displaystyle 2.0$ g sample containing $\displaystyle \mathrm{MnO}_2$ is treated with HCl liberating $\displaystyle \mathrm{Cl}_2$. The $\displaystyle \mathrm{Cl}_2$ gas is passed into a solution of KI and $\displaystyle 60.0$ mL of $\displaystyle 0.1 \mathrm{M} \mathrm{Na}_2 \mathrm{~S}_2 \mathrm{O}_3$ is required to titrate the liberated iodine. The percentage of $\displaystyle \mathrm{MnO}_2$ in the sample is \_\_\_\_. (Nearest integer) [Atomic masses (in u) $\displaystyle \mathrm{Mn}=55 ; \mathrm{Cl}=35.5 ; \mathrm{O}=16, \mathrm{I}=127, \mathrm{Na}=23, \mathrm{~K}=39$, $\displaystyle \mathrm{S}=32$ ]