$A$ mixture of $SO_2$ and $O_2$ at $5 \, atm$ pressure reacts $30\%$ until equilibrium is reached. Determine the total pressure of the equilibrium mixture in $atm$.
$2SO_{2(g)} + O_{2(g)} \rightleftharpoons 2SO_{3(g)}$

$28 \, g$ of $N_2$ and $6 \, g$ of $H_2$ were kept at $400 \, ^oC$ in a $1 \, L$ vessel. The equilibrium mixture contained $27.54 \, g$ of $NH_3$. The approximate value of $K_c$ for the reaction $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$ is (in $L^2 \, mol^{-2}$):

$K_{c}$ for the following reaction is $99.0$: $A_{2(g)} \rightleftharpoons B_{2(g)}$. In a $1 \ L$ flask,$2 \ moles$ of $A_{2}$ were heated to $T(K)$ and equilibrium was reached. The concentrations at equilibrium of $A_{2}$ and $B_{2}$ are $C_{1}(A_{2})$ and $C_{2}(B_{2})$ respectively. Now,$1 \ mole$ of $A_{2}$ was added to the flask and heated to $T(K)$ to establish equilibrium again. The concentrations of $A_{2}$ and $B_{2}$ are $C_{3}(A_{2})$ and $C_{4}(B_{2})$ respectively. What is the value of $C_{3}(A_{2})$ in $mol \ L^{-1}$?

The incorrect expression among the following is:

Attainment of the equilibrium $A_{(g)} \rightleftharpoons 3C_{(g)} + 2B_{(g)}$ gave the following graph. Find the correct option. $(\text{Percentage dissociation} = \text{fraction dissociated} \times 100)$

For the reaction $2A_{(g)} + B_{(g)} \rightleftharpoons 3C_{(g)} + D_{(g)}$,two moles each of $A$ and $B$ were taken into a $1 \ L$ flask. Which of the following must always be true when the system attains equilibrium?