The degree of dissociation of ${\mathrm{SO}}_3$ is $\alpha$ at equilibrium pressure ${\mathrm{P}}_0$. ${\mathrm{K}}_{\mathrm{P}}$ for $2{\mathrm{SO}}_3\left(\mathrm{g}\right)\rightleftharpoons 2{\mathrm{SO}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$ is:

Consider the following hypothetical equilibrium:

$2\mathrm{B}\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{B}}_2\left(\mathrm{g}\right)$

If $\mathrm{d}$ is observed vapour density and $\mathrm{D}$ is theoretical vapour density, then degree of association will be:

${\mathrm{SO}}_3\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{SO}}_2\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)$

If observed vapour density of mixture at equilibrium is $35$ then find out value of $\alpha$?

For equilibrium:

${\mathrm{N}}_2{\mathrm{O}}_4\left(\mathrm{g}\right)\rightleftharpoons 2{\mathrm{NO}}_2\left(\mathrm{g}\right)$

the observed vapour density of ${\mathrm{N}}_2{\mathrm{O}}_4$ is $40$ at $350 \mathrm{K}$. Calculate percentage dissociation of ${\mathrm{N}}_2{\mathrm{O}}_4\left(\mathrm{g}\right)$ at $350 \mathrm{K}$?