At $800°\mathrm{C}$, the following equilibrium is established as
${\text{F}}_2\left(\text{g}\right)\rightleftharpoons 2\text{F}\left(\text{g}\right)$
The composition of equilibrium may be determined by measuring the rate of effusion of the mixture through a pin hole. It is found that $800°\mathrm{C}$ and $1 \mathrm{atm}$ mixture effuses $1.6$ times as fast as ${\mathrm{SO}}_2$ effuses under the similar conditions. (At. wt. of $\mathrm{F}=19$). What is the value of ${\mathrm{K}}_{\mathrm{p}}$ (in atm) ?