Consider the following liquid-vapour equilibrium.
$Liquid \rightleftharpoons Vapour$
Which of the following relations is correct?

In the reaction $A + 2B \rightleftharpoons 2C$,if $2$ moles of $A$,$3.0$ moles of $B$ and $2.0$ moles of $C$ are placed in a $2.0 \ L$ flask and the equilibrium concentration of $C$ is $0.5 \ mol/L$. The equilibrium constant $K_c$ for the reaction is:

$1 \ mol$ of $N_2$ and $2 \ mol$ of $H_2$ are allowed to react in a $1 \ dm^3$ vessel. At equilibrium,$0.8 \ mol$ of $NH_3$ is formed. What is the concentration of $H_2$ at equilibrium (in $M$)?

The equilibrium constants $K_{p_1}$ and $K_{p_2}$ for the reactions $X \rightleftharpoons 2Y$ and $Z \rightleftharpoons P + Q$ are in the ratio of $1 : 4$. If the degree of dissociation of $X$ is $2$ times that of $Z$,then the ratio of total pressure $(P_1 : P_2)$ at these equilibria is: (Assume degree of dissociation for both reactions are very small)

In a reaction,$A + B \rightleftharpoons C + D$,$40 \%$ of $B$ has reacted at equilibrium,when $1 \ mol$ of $A$ was heated with $1 \ mol$ of $B$ in a $10 \ L$ closed vessel. The value of $K_C$ is

Which of the following oxides of nitrogen is the most stable?