In which one of the following equilibria,$K_p \neq K_c$?

At $444 \, ^\circ C$,the equilibrium constant for the reaction $HI \rightleftharpoons 1/2 H_2 + 1/2 I_2$ is $64$. What will be the equilibrium constant for the reaction $H_2 + I_2 \rightleftharpoons 2HI$?

$2NO_2 \rightleftharpoons 2NO + O_2$; $K = 1.6 \times 10^{-12}$. For $NO + \frac{1}{2}O_2 \rightleftharpoons NO_2$,$K' = $

In a $1 \ L$ closed container,$4 \ moles$ of $PCl_5$ are heated. If $80\%$ of $PCl_5$ remains undissociated at equilibrium,what is the value of the equilibrium constant $(K_c)$?

For the reactions $N_{2(g)} + O_{2(g)} \rightleftharpoons 2NO_{(g)}$ and $\frac{1}{2}N_{2(g)} + \frac{1}{2}O_{2(g)} \rightleftharpoons NO_{(g)}$,if the equilibrium constants are $K_1$ and $K_2$ respectively,then their relationship is:

$A$ homogeneous ideal gaseous reaction $AB_{2(g)} \rightleftharpoons A_{(g)} + 2B_{(g)}$ is carried out in a $25 \ L$ flask at $27^{\circ}C$. The initial amount of $AB_{2}$ was $1 \ mole$ and the equilibrium pressure was $1.9 \ atm$. The value of $K_{P}$ is $x \times 10^{-2}$. The value of $x$ is $...$ (Integer answer)