$x A_{(s)} \rightleftharpoons y B_{(g)} + z C_{(g)}$. If $\frac{K_c}{K_p} = (RT)^{-2}$,then which is correct?

For the reaction $A + B \rightleftharpoons C + D$ at $298 \ K$,the equilibrium constant is $10.0$. If the initial concentration of all four species is $1 \ M$,what will be the equilibrium concentration of $D$ (in $mol \ L^{-1}$)?

For the reversible reaction, $N_{2(g)} + 3H_{2(g)} \rightleftharpoons 2NH_{3(g)}$. When the partial pressure is measured in atmosphere, the value of $K_p$ at $500^{\circ}\text{C}$ is $1.44 \times 10^{-5}$. The value of $K_c$ when the concentration is expressed in $\text{mol L}^{-1}$ is:

At $1050 \ K$,for the chemical reaction $FeO_{(s)} + CO_{(g)} \rightleftharpoons Fe_{(s)} + CO_{2_{(g)}}$; $K_p = 0.25$. What are the equilibrium partial pressures of $CO_{(g)}$ and $CO_{2_{(g)}}$ at $1050 \ K$,if the initial partial pressures are: $P_{CO_{(g)}} = 1.6 \ atm$ and $P_{CO_{2_{(g)}}} = 0.8 \ atm$?

For the reaction at $25\,^{\circ}C$,$N_2O_{4(g)} \rightleftharpoons 2NO_{2(g)}$,if $\Delta G^{\circ}_f$ for $N_2O_4$ and $NO_2$ are $23.49 \, kcal$ and $12.39 \, kcal$ respectively,then $K_p$ for the reaction is:

For the reaction $N_2O_{4_{(g)}} \rightleftharpoons 2NO_{2_{(g)}}$ at $298 \ K$,the equilibrium constant $K_p$ is $0.14 \ atm$. Calculate the value of $K_c$. $(R = 0.082 \ L \ atm \ K^{-1} \ mol^{-1})$