Given following reaction,
${\mathrm{NaClO}}_3+\mathrm{Fe}\text{\hspace{0.17em}\hspace{0.17em}}\to {\mathrm{O}}_2+\mathrm{FeO}+\mathrm{NaCl}$
In the above reaction 492 L of  ${\mathrm{O}}_2$ is obtained at 1 atm and 300 K temperature.
Determine mass of ${\mathrm{NaClO}}_3$  required in nearest whole number  (in kg).
$\left(\mathrm{R}=0.082\mathrm{L}\mathrm{atm}{\mathrm{mol}}^{-1}{\mathrm{K}}^{-1}\right)$