$A$ 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 $atm$.
$2SO_{2(g)} + O_{2(g)} \rightleftharpoons 2SO_{3(g)}$

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?

In a closed vessel at $448^{\circ} C$,$0.5 \ mol$ of $H_2$ and $0.5 \ mol$ of $I_2$ react to form hydrogen iodide.
Reaction: $H_{2(g)} + I_{2(g)} \rightleftharpoons 2HI_{(g)}$,$K_c = 50$.
$(i)$ Calculate the moles of $I_2$ that remain unreacted at equilibrium.
$(ii)$ Calculate $K_p$.

Match the items in List-$X$ with List-$Y$ and select the correct option.

List-$X$	List-$Y$
$(A)$ Active mass	$(i)$ $\Delta n = 0$
$(B)$ Equilibrium constant	$(ii)$ Molar concentration
$(C)$ $A + \text{Heat} \rightleftharpoons B$	$(iii)$ Van't Hoff equation
$(D)$ $2A_{(g)} + B_{(g)} \rightleftharpoons 3C_{(g)}$	$(iv)$ Favoured by increase in temperature
	$(v)$ Chemical equilibrium

$K_{c}$ 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 $mol \ L^{-1}$?

Calculate the partial pressure of carbon monoxide from the following:
$CO_{2(g)} + C_{(s)} \rightleftharpoons 2CO_{(g)}$ ; $K_{p1} = 2$
$CaCO_{3(s)} \rightleftharpoons CaO_{(s)} + CO_{2(g)}$ ; $K_{p2} = 8 \times 10^{-2}$