For the reaction $PCl_5(g) \rightleftarrows PCl_3(g) + Cl_2(g)$,which condition is correct?

The equilibrium constants for the reactions $X \rightleftharpoons 2Y$ and $Z \rightleftharpoons P + Q$ are $K_{1}$ and $K_{2}$,respectively. If the initial concentrations and the degree of dissociation of $X$ and $Z$ are the same,the ratio $K_{1} / K_{2}$ is

Air containing $79\%$ of nitrogen and $21\%$ of oxygen by volume is heated at $2200 \ K$ and $1 \ atm$ until equilibrium is established according to the reaction $N_{2(g)} + O_{2(g)} \rightleftharpoons 2NO_{(g)}$. If the $K_p$ of the reaction is $1.1 \times 10^{-3}$,calculate the amount of nitric oxide produced in terms of volume percent.

One mole of $H_2O$ and one mole of $CO$ are taken in a $10 \ L$ vessel and heated to $725 \ K$. At equilibrium,$40 \%$ of water (by mass) reacts with $CO$ according to the equation:
$H_2O_{(g)} + CO_{(g)} \longleftrightarrow H_{2(g)} + CO_{2(g)}$
Calculate the equilibrium constant $(K_c)$ for the reaction.

For the reaction $2A_{(g)} + B_{(g)} \rightleftharpoons 3C_{(g)} + D_{(g)}$,$2 \ mol$ each of $A$ and $B$ are taken in a flask. Which of the following will always be true when the system reaches equilibrium?

The thermal dissociation equilibrium of $CaCO_{3(s)}$ is studied under different conditions.
$CaCO_{3(s)} \rightleftharpoons CaO_{(s)} + CO_{2(g)}$
For this equilibrium,the correct statement$(s)$ is (are):
$(A)$ $\Delta H$ is dependent on $T$
$(B)$ $K$ is independent of the initial amount of $CaCO_{3}$
$(C)$ $K$ is dependent on the pressure of $CO_{2}$ at a given $T$
$(D)$ $\Delta H$ is independent of the catalyst,if any