For the reaction $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$,what is the relationship between $K_p$ and $K_c$?

In the reaction,$H_2 + I_2 \rightleftharpoons 2HI$. In a $2 \ L$ flask,$0.4 \ mol$ of each $H_2$ and $I_2$ are taken. At equilibrium,$0.5 \ mol$ of $HI$ are formed. What will be the value of equilibrium constant,$K_c$?

For the reactions $(1)$ and $(2)$ :
$A \rightleftharpoons B + C \dots (1)$
$D \rightleftharpoons 2E \dots (2)$
Given $K_{P_1} : K_{P_2} = 9 : 1$.
If the degree of dissociation of $A$ and $D$ is the same,then the total pressure at equilibria $(1)$ and $(2)$ are in the ratio (Assume reactions are started with equal number of moles of $A$ and $D$). (in $: 1$)

The gas phase reaction $2A_{(g)} \rightleftharpoons A_{2(g)}$ at $400 \ K$ has $\Delta G^{\circ} = +25.2 \ kJ \ mol^{-1}$. The equilibrium constant $K_{C}$ for this reaction is $...... \times 10^{-2}$. (Round off to the nearest integer) $[$Use: $R = 8.3 \ J \ mol^{-1} \ K^{-1}$,$\ln 10 = 2.3$,$\log_{10} 2 = 0.30$,$1 \ atm = 1 \ bar]$ $[$antilog $(-3.3) = 5.01 \times 10^{-4}]$

For the elementary reaction $A_{2(g)} + B_{2(g)} \rightleftharpoons 2AB_{(g)}$,the rate of the forward reaction is given by $r_f = 1.7 \times 10^{-18} [A_2][B_2]$. If the rate of decomposition of gaseous $AB$ into $A_2$ and $B_2$ is given by $r_r = 2.4 \times 10^{-21} [AB]^2$,then the equilibrium constant for the formation of $AB$ from $A_2$ and $B_2$ will be ...

For the following three equilibria $X, Y$,and $Z$ in the gaseous state at $300 \ K$,the increasing order of the ratio of $K_p$ to $K_c$ is:
$X: 2SO_2 + O_2 \rightleftharpoons 2SO_3$
$Y: PCl_5 \rightleftharpoons PCl_3 + Cl_2$
$Z: 2HI \rightleftharpoons H_2 + I_2$