The vapour density of undecomposed ${\mathrm{N}}_2{\mathrm{O}}_4$ is $46$. When heated, vapor density decreases to $24.5$ due to its dissociation to ${\mathrm{NO}}_2$. The percentage dissociation of ${\mathrm{N}}_2{\mathrm{O}}_4$ at the final temperature is

For which of the following reactions, the degree of dissociation cannot be calculated from the vapour density data.

$\mathrm{I}. 2\mathrm{HI} \left(\mathrm{g}\right)\rightleftharpoons {\mathrm{H}}_2 \left(\mathrm{g}\right)+{\mathrm{I}}_2 \left(\mathrm{g}\right)$

$\mathrm{II}. 2{\mathrm{NH}}_3 \left(\mathrm{g}\right)\rightleftharpoons {\mathrm{N}}_2 \left(\mathrm{g}\right)+3{\mathrm{H}}_2 \left(\mathrm{g}\right)$

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

$\mathrm{IV}. {\mathrm{PCl}}_5 \left(\mathrm{g}\right)\rightleftharpoons {\mathrm{PCl}}_3 \left(\mathrm{g}\right)+{\mathrm{Cl}}_2 \left(\mathrm{g}\right)$

For ${\mathrm{NH}}_4\mathrm{HS}\left(\mathrm{s}\right)\rightleftharpoons {\mathrm{NH}}_3\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{S}\left(\mathrm{g}\right)$, if${\mathrm{K}}_{\mathrm{P}}=64 {\mathrm{atm}}^2$, the equilibrium pressure of the mixture is

Given equilibrium constants for the following reactions at $1200°\mathrm{C}$.

$$\begin{gathered} \mathrm{C}\left(\mathrm{g}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\rightleftharpoons 2\mathrm{CO}\left(\mathrm{g}\right), {\mathrm{K}}_{{\mathrm{P}}_1}=1.47\times {10}^3 \\ \mathrm{CO}\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{CO}}_2\left(\mathrm{g}\right), {\mathrm{K}}_{{\mathrm{P}}_2}=2\times {10}^6 \end{gathered}$$

Calculate ${\mathrm{K}}_{\mathrm{P}}$ for the reaction$\mathrm{C} \left(\mathrm{g}\right)+{\mathrm{O}}_2 \left(\mathrm{g}\right)\rightleftharpoons {\mathrm{CO}}_2 \left(\mathrm{g}\right)$.