The distribution law is applied for the distribution of a solute between which of the following pairs of solvents?

For the reaction $3A + B \rightleftharpoons 2C + D$,if the equilibrium concentrations of $A, B,$ and $C$ are $0.03 \ M, 0.01 \ M,$ and $0.008 \ M$ respectively,what is the initial concentration of $A$ (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 . . . . . . $\times 10^{-1} \text{ atm}$.

$13.8 \,g$ of $N_{2}O_{4}$ was placed in a $1 \,L$ reaction vessel at $400 \,K$ and allowed to attain equilibrium.
$N_{2}O_{4(g)} \rightleftharpoons 2NO_{2(g)}$
The total pressure at equilibrium was found to be $9.15 \,bar$. Calculate $K_{c}$,$K_{p}$,and the partial pressures at equilibrium.

Consider the following reversible first-order reaction of $X$ at an initial concentration $[X]_{0}$. The values of the rate constants are $K_{f} = 2 \ s^{-1}$ and $K_{b} = 1 \ s^{-1}$.
$X \underset{K_{b}}{\stackrel{K_{f}}{\rightleftharpoons}} Y$
Which of the following plots correctly represents the concentration of $X$ and $Y$ as a function of time?

$S_1$: 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.