For the formation of $NH_{3(g)}$ from its constituent elements,which of the relations between the reaction quotient $(Q)$ and equilibrium constant $(K_C)$ is correct for the backward reaction?

For the reaction $PCl_5(g) \rightleftharpoons PCl_3(g) + Cl_2(g)$,the equilibrium constant $K_p$ is $16$. If the volume of the container is reduced to $\frac{1}{2}$ of its original value,what will be the value of $K_p$ at the same temperature?

The following equilibria are given:
$N_2 + 3H_2 \rightleftharpoons 2NH_3 ; K_1$
$N_2 + O_2 \rightleftharpoons 2NO ; K_2$
$H_2 + \frac{1}{2}O_2 \rightleftharpoons H_2O ; K_3$
The equilibrium constant of the reaction $2NH_3 + \frac{5}{2}O_2 \rightleftharpoons 2NO + 3H_2O$ in terms of $K_1, K_2$ and $K_3$ is:

The value of $K_{C}$ is $64$ at $800 \ K$ for the reaction $N_{2(g)} + 3H_{2(g)} \rightleftharpoons 2NH_{3(g)}$.
The value of $K_{C}$ for the following reaction is:
$NH_{3(g)} \rightleftharpoons \frac{1}{2}N_{2(g)} + \frac{3}{2}H_{2(g)}$

At $T(K)$,the equilibrium constant of $A_{2}(g) + B_{2}(g) \rightleftharpoons C(g)$ is $2.7 \times 10^{-5}$. What is the equilibrium constant for $\frac{1}{3}A_{2}(g) + \frac{1}{3}B_{2}(g) \rightleftharpoons \frac{1}{3}C(g)$ at the same temperature?

In the equilibrium $AB \rightleftharpoons A + B$; if the equilibrium concentration of $A$ is doubled,the equilibrium concentration of $B$ would become: