What is the vapour density of $O_2$ gas?

For the following equilibrium $N_2O_4 \rightleftharpoons 2NO_2$ in gaseous phase,$NO_2$ is $50\%$ of the total volume when equilibrium is set up. Hence,the percentage of dissociation of $N_2O_4$ is.......$\%$

$AB_{3(g)}$ dissociates as:
$AB_{3(g)} \rightleftharpoons AB_{2(g)} + \frac{1}{2} B_{2(g)}$. When the initial pressure of $AB_3$ is $800 \ torr$ and the total pressure developed at equilibrium is $900 \ torr$,what percentage of $AB_{3(g)}$ is dissociated?

At temperature,$T$,a compound $AB_{2(g)}$ dissociates according to the reaction; $2AB_{2(g)} \rightleftharpoons 2AB_{(g)} + B_{2(g)}$ with a degree of dissociation $x$,which is small compared with unity. The expression for $K_p$,in terms of $x$ and the total pressure,$P$ is

For a $10^{-2} \ M \ HCN$ solution with $[H^+] = 10^{-3} \ M$,find the value of the degree of dissociation in percentage. (in $\%$)

$2SO_3 \rightleftharpoons 2SO_2 + O_2$. Initially,$3$ moles of $SO_3$ were heated. If the degree of dissociation of $SO_3$ is $40\%$,find the total number of moles at equilibrium.