For the reaction $CuSO_4 \cdot 5H_2O_{(s)} \rightleftharpoons CuSO_4 \cdot 3H_2O_{(s)} + 2H_2O_{(g)}$,which of the following is a correct representation?

One mole each of $He$ and $A(g)$ are taken in a $10 \text{ L}$ closed flask and heated to $400 \text{ K}$ to establish the following equilibrium: $A(g) \rightleftharpoons B(g)$. $K_{c}$ for this reaction at $400 \text{ K}$ is $4.0$. The partial pressures (in $\text{atm}$) of $He$ and $B(g)$ are respectively (at equilibrium) (Assume $He$, $A(g)$ and $B(g)$ behave as ideal gases) (Given: $R = 0.082 \text{ L atm K}^{-1} \text{ mol}^{-1}$)

For the reaction $XCO_{3(s)} \rightleftharpoons XO_{(s)} + CO_{2(g)},$ $K_p = 1.642 \text{ atm}$ at $727^{\circ}C.$ If $4 \text{ moles}$ of $XCO_{3(s)}$ were placed into a $50 \text{ L}$ container and heated to $727^{\circ}C,$ what mole percent of the $XCO_3$ remains unreacted at equilibrium?

One mole of $N_2O_{4(g)}$ at $300 \ K$ is kept in a closed container under $1 \ atm$ pressure. It is heated to $600 \ K$ when $20 \%$ of $N_2O_{4(g)}$ decomposes to $NO_{2(g)}$. The resultant pressure at $600 \ K$ is $..... \ atm$.

$10 \%$ of $PCl_5$ decomposes at a definite temperature and $4 \ atm$ pressure. At the same temperature,if $20 \%$ of $PCl_5$ decomposes,find the pressure. (Temperature remains constant.) (in $atm$)

Consider the reaction $N_{2(g)} + 3H_{2(g)} \rightleftharpoons 2NH_{3(g)}$. The equilibrium constant of the above reaction is $K_p$. If pure ammonia is left to dissociate,the partial pressure of ammonia at equilibrium is given by (Assume that $P_{NH_3} \ll P_{total}$ at equilibrium and $P$ is the total pressure).