What is the equilibrium expression for the reaction $P_{4(s)} + 5O_{2(g)} \rightleftharpoons P_4O_{10(s)}$?

If the equilibrium constant for the reaction $A + 3B \rightleftharpoons 2C$ is $K_1$,then the equilibrium constant $K_2$ for the reaction $2C \rightleftharpoons A + 3B$ should be:

State the law of chemical equilibrium for an equilibrium process.

How is the direction of a reaction predicted?

The following equilibria are given:
$N_2 + 3H_2 \rightleftharpoons 2NH_3 ; K_1$
$N_2 + O_2 \rightleftharpoons 2NO ; K_2$
$H_2 + \frac{1}{2}O_2 \rightleftharpoons H_2O ; K_3$
The equilibrium constant of the reaction $2NH_3 + \frac{5}{2}O_2 \rightleftharpoons 2NO + 3H_2O$ in terms of $K_1, K_2$ and $K_3$ is:

In a chemical equilibrium $A + B \rightleftharpoons C + D$,when $1 \, mol$ each of two reactants are mixed,$0.5 \, mol$ each of the products are formed. The equilibrium constant is