Consider the following gas phase reaction being carried out in a closed vessel at $25^\circ\text{C}$: $2A(g) \rightarrow 4B(g) + C(g)$. The table provides the total pressure of the system at different time intervals. Calculate the pressure of $C(g)$ at $30$ minutes time interval.

Time (min)	Total pressure (mm Hg)
$30$	$300$
$\infty$	$600$

$S_1$: In case of endothermic reactions,the equilibrium shifts in the forward direction on increasing temperature.
$S_2$: The value of $K_{eq}$ depends only on temperature and is independent of pressure.
$S_3$: For the reaction,$H_2(g) + I_2(g) \rightleftharpoons 2HI(g)$,the equilibrium constant,$K_{eq}$ is dimensionless because the number of moles of gaseous products equals the number of moles of gaseous reactants.

Assign $A, B, C, D$ from the given type of reaction.
$PbCl_2 \downarrow + H_2SO_4 \rightleftharpoons PbSO_4 \downarrow + 2HCl$

At a certain temperature,the equilibrium constant $K_c$ is $0.25$ for the reaction:
$A_{2(g)} + B_{2(g)} \rightleftharpoons C_{2(g)} + D_{2(g)}$
If we take $1 \ mol$ of each of the four gases in a $10 \ L$ container,what would be the equilibrium concentration of $A_{2(g)}$ (in $M$)?

Solid carbon, $CaO$ and $CaCO_3$ are mixed and allowed to attain equilibrium at $T \text{ K}$. $CaCO_3(s) \rightleftharpoons CaO(s) + CO_2(g)$ $K_{p1} = 0.08 \text{ atm}$. $C(s) + CO_2(g) \rightleftharpoons 2CO(g)$ $K_{p2} = 2 \text{ atm}$. The partial pressure of $CO$ is . . . . . . $\times 10^{-1} \text{ atm}$.

The equilibrium constant of a reaction at $298 \ K$ is $5 \times 10^{-3}$ and at $1000 \ K$ is $2 \times 10^{-5}$. What is the sign of $\Delta H$ for the reaction?