Which of the following expressions is true regarding the formation of $PCl_{5(g)}$?
$PCl_{3(g)} + Cl_{2(g)} \rightleftharpoons PCl_{5(g)}$

For the reaction $2SO_{2(g)} + O_{2(g)} \rightleftharpoons 2SO_{3(g)}$ at $298 \ K$,the $K_c$ is $7 \times 10^{25}$. Calculate $K_c$ for the reaction $SO_{3(g)} \rightleftharpoons SO_{2(g)} + \frac{1}{2}O_{2(g)}$.

$2 SO_{2(g)} + O_{2(g)} \rightleftharpoons 2 SO_{3(g)}$
In an equilibrium mixture,the partial pressures are
$P_{SO_{3}} = 43 \ kPa$,$P_{O_{2}} = 530 \ Pa = 0.53 \ kPa$,and
$P_{SO_{2}} = 45 \ kPa$. The equilibrium constant $K_{p} = ...... \times 10^{-2} \ kPa^{-1}$. (Nearest integer)

For a reversible reaction $A \rightleftharpoons B$,the pre-exponential factor is the same for both the forward and backward reactions and has a value of $20 \ s^{-1}$. If the enthalpy change for the forward reaction is $-41.5 \ kJ \ mol^{-1}$,the value of the equilibrium constant at $500 \ K$ is:

For the reactions $N_{2(g)} + O_{2(g)} \rightleftharpoons 2NO_{(g)}$ and $NO_{(g)} \rightleftharpoons 1/2N_{2(g)} + 1/2O_{2(g)}$,the equilibrium constants are $K_1$ and $K_2$ respectively. What is the relationship between $K_1$ and $K_2$?

For the reaction $CO_{(g)} + 1/2 O_{2(g)} \rightleftharpoons CO_{2(g)}$,the value of $K_P/K_C$ is