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

In the reaction $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$,initially $1 \text{ mole}$ each of $PCl_5$ and $PCl_3$ are present. At equilibrium,$x \text{ moles}$ of $PCl_5$ remain. What is the total number of moles at equilibrium (in $- x$)?

$0.6 \ mol$ of $NH_3$ in a reaction vessel of $2 \ dm^3$ capacity was brought to equilibrium. The vessel was then found to contain $0.15 \ mol$ of $H_2$ formed by the reaction $2NH_{3(g)} \rightleftharpoons N_{2(g)} + 3H_{2(g)}$. Which of the following statements is true?

For the reaction $NH_2COONH_{4(s)} \rightleftharpoons 2NH_{3(g)} + CO_{2(g)}$. If the equilibrium pressure is $3X \ bar$,then $\Delta G_r^o$ will be:

For the reaction $2P_{(g)} + Q_{(g)} \rightleftharpoons R_{(g)} + S_{(g)}$; $K_C = 10^{12}$. If the initial moles of $P, Q, R, S$ are $2, 1, 7$ and $3$ moles respectively in a $1 \ L$ vessel,find the equilibrium concentration of $P$.

For the reaction $N_2 + O_2 \rightleftharpoons 2NO$ at $300 \, ^\circ C$,the value of $K_c$ is $9 \times 10^{-4}$. If equivalent amounts of $N_2$ and $O_2$ are used,what is the concentration of $NO$ at equilibrium (in terms of $a$) (in $, a$)?