For the given equilibrium reaction $H_{2(g)} + I_{2(g)} \rightleftharpoons 2 HI_{(g)}$,choose the correct equation to calculate $K_p$.

For the reaction: $SO_{2(g)} + \frac{1}{2} O_{2(g)} \rightleftharpoons SO_{3(g)}$,$K_P = 2 \times 10^{12}$ at $27^{\circ} C$ and $1 \ atm$ pressure. The $K_C$ for the same reaction is $......... \times 10^{13}$. (Nearest integer)
(Given $R = 0.082 \ L \ atm \ K^{-1} \ mol^{-1}$)

For a reaction $2A_{(g)} \rightleftharpoons 2B_{(g)} + C_{(g)}$,$K_c = 3.75 \times 10^{-6}$ at $1069 \ K$. The approximate value of $K_p$ for this reaction at the same temperature is $(R = 0.082 \ L \ bar \ mol^{-1} \ K^{-1})$.

For the reaction $H_2 + I_2 \rightleftharpoons 2HI$,the equilibrium concentrations of $H_2$,$I_2$,and $HI$ are $8.0 \ mol \ L^{-1}$,$3.0 \ mol \ L^{-1}$,and $28.0 \ mol \ L^{-1}$ respectively. The equilibrium constant $(K_c)$ of the reaction is: (in $.66$)

In a chemical equilibrium,the rate constant of the backward reaction is $7.5 \times 10^{-4}$ and the equilibrium constant is $1.5$. The rate constant of the forward reaction is:

For the reaction $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$,$1 mol$ of $PCl_5$ is taken at $5 atm$ pressure. If $50\%$ of $PCl_5$ dissociates at equilibrium,calculate $K_p$.