At $T \ K$,the $K_C$ value for the reaction $\frac{1}{3} N_{2(g)} + H_{2(g)} \rightleftharpoons \frac{2}{3} NH_{3(g)}$ is $50$. The $K_C$ value for the reaction $2 NH_{3(g)} \rightleftharpoons N_{2(g)} + 3 H_{2(g)}$ at the same temperature is:

If $Ag^{+} + NH_3 \rightleftharpoons [Ag(NH_3)]^+$; $K_1 = 1.6 \times 10^3$ and $[Ag(NH_3)]^+ + NH_3 \rightleftharpoons [Ag(NH_3)_2]^+$; $K_2 = 6.8 \times 10^3$. Then the formation constant of $[Ag(NH_3)_2]^+$ is:

For the reaction $:$
$CH_{4(g)} + 2O_{2(g)} \rightleftharpoons CO_{2(g)} + 2H_2O_{(l)},$
$\Delta H_r = -170.8 \ kJ \ mol^{-1},$ which of the following statements is not true $?$

$2 NOCl_{(g)} \rightleftharpoons 2 NO_{(g)} + Cl_{2(g)}$
In an experiment,$2.0 \ mol$ of $NOCl$ was placed in a $1 \ L$ flask and the concentration of $NO$ after equilibrium was established,was found to be $0.4 \ mol/L$. The equilibrium constant at $30^{\circ} C$ is $....... \times 10^{-4}$.

Explain the use of the equilibrium constant to predict the extent of a reaction with an example.

For the reaction ${N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)}$,the equilibrium constant ${K_p = 35}$ at a given temperature. Calculate the values of ${K_p}$ for the following reactions at the same temperature:
$(i) \ 2NH_3(g) \rightleftharpoons N_2(g) + 3H_2(g)$
$(ii) \ \frac{1}{2}N_2(g) + \frac{3}{2}H_2(g) \rightleftharpoons NH_3(g)$