For the reaction $N_2 + 3H_2 \rightleftharpoons 2NH_3$,what is the relationship between $\Delta H$ and $\Delta E$?

$0.5 \ mol$ of $CaCO_3(s)$ is heated in a $500 \ mL$ closed vessel at $400 \ K$. The reaction is $CaCO_{3(s)} \rightleftharpoons CaO(s) + CO_{2(g)}$. If the equilibrium constant $K_c = 0.9 \ mol \ L^{-1}$,calculate the amount of $CO_2$ in $mol$ at equilibrium and the percentage of the reaction completed.

Two equilibria,$AB \rightleftharpoons A^{+} + B^{-}$ and $AB + B^{-} \rightleftharpoons AB_2^-$,are simultaneously maintained in a solution with equilibrium constants $K_1$ and $K_2$ respectively. The ratio of $[A^{+}]$ to $[AB_2^-]$ in the solution is

$3.00 \ mol$ of $PCl_5$ kept in $1 \ L$ closed reaction vessel was allowed to attain equilibrium at $380 \ K$. If $1.59 \ mol$ of reactant was converted into the product at equilibrium,then $K_c$ is:

For a reaction; $A + B \rightleftharpoons C + D$,the initial concentrations of $A$ and $B$ are equal,but the equilibrium concentration of $C$ is twice that of the equilibrium concentration of $A$. The $K_c$ is:

$2NOBr(g) \rightleftharpoons 2NO(g) + Br_2(g)$. If nitrosyl bromide $(NOBr)$ is $40\%$ dissociated at a certain temperature and a total pressure of $0.3 \ atm$,what is the $K_P$ for the reaction $2NO(g) + Br_2(g) \rightleftharpoons 2NOBr(g)$?