The vapour density of a mixture containing $NO_2$ and $N_2O_4$ is $27.6$. The mole fraction of $N_2O_4$ in the mixture is

$0.1 \ mol$ of $H_2S_{(g)}$ is kept in a $0.4 \ L$ vessel at $1000 \ K$. For the reaction $2 H_2S_{(g)} \rightleftharpoons 2 H_{2(g)} + S_{2(g)}$,$K_c = 10^{-6}$. The percentage dissociation of $H_2S$ is.......$\%$

Consider the following reaction in a sealed vessel at equilibrium with concentrations of $N_2 = 3.0 \times 10^{-3} \ M$,$O_2 = 4.2 \times 10^{-3} \ M$,and $NO = 2.8 \times 10^{-3} \ M$.
$2 \ NO_{(g)} \rightleftharpoons N_{2_{(g)}} + O_{2_{(g)}}$
If $0.1 \ mol \ L^{-1}$ of $NO_{(g)}$ is taken in a closed vessel,what will be the degree of dissociation $(\alpha)$ of $NO_{(g)}$ at equilibrium?

The vapor density of a volatile substance with respect to $CH_4$ $(CH_4 = 1)$ is $4$. What is its molecular weight?

For the equilibrium $PCl_{5_{(g)}} \rightleftharpoons PCl_{3_{(g)}} + Cl_{2_{(g)}}$,the observed vapour density of the mixture is $80$. Given atomic masses $P = 31$ and $Cl = 35.5$,the degree of dissociation of $PCl_{5_{(g)}}$ is approximately....$\%$

$4 \ mol$ of $PCl_5$ is heated in a closed vessel at a constant temperature. If the degree of dissociation for $PCl_5$ is $0.5$,what will be the total number of moles at equilibrium?