Gaseous $N_2O_4$ dissociate into gaseous $NO_2$ according to the reaction $N_2O_4(g) \to 2NO_2(g)$. At 300 K and 1 atm pressure , the degree of dissociation of $N_2O_4$ is $0.2$. If one mole of $N_2O_4$ gas is contained in a vessel, then the density of the equilibrium mixture is :

Question

$\begin{array}{1 1} 1.56\;g/L \\ 3.11\;g/L \\ 4.56 \;g/L \\ 6.22 \;g\;L \end{array} $