The figure shows the change in concentration of species $A$ and $B$ as a function of time. The equilibrium constant $K_C$ for the reaction $2A_{(g)} \rightleftharpoons B_{(g)}$ is

At $200^{\circ} C$,nitric oxide reacts with oxygen to form nitrogen dioxide as follows: $2 NO(g) + O_2(g) \rightleftharpoons 2 NO_2(g)$,$K_C = 3 \times 10^6$. In a mixture of the three species at equilibrium,we can accurately predict that:

Assertion: Reaction quotient is defined in the same way as equilibrium constant at any stage of the reaction.
Reason: If $Q_c < K_c$,the reaction moves in the direction of reactants.

$A$ reaction is $A + B \rightleftharpoons C + D$. Initially,we start with equal concentrations of $A$ and $B$. At equilibrium,the number of moles of $C$ is two times that of $A$. What is the equilibrium constant $(K_c)$ of the reaction?

$3.1 \ mol$ of $FeCl_3$ and $3.2 \ mol$ of $NH_4SCN$ are added to $1 \ L$ of water. At equilibrium,$3.0 \ mol$ of $FeSCN^{2+}$ is formed. The equilibrium constant $K_c$ for the reaction is:
$Fe^{3+} + SCN^{-} \rightleftharpoons FeSCN^{2+}$

At a given temperature,the equilibrium constant for the reaction $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$ is $2.4 \times 10^{-3}$. At the same temperature,the equilibrium constant for the reaction $PCl_{3(g)} + Cl_{2(g)} \rightleftharpoons PCl_{5(g)}$ is: