What is the equilibrium expression for the reaction
P₄ (s) + 5O₂ $$\leftrightharpoons$$ P₄O₁₀ (s)?

For the reaction, CO(g) + Cl₂(g) $$\leftrightharpoons$$ COCl₂(g) the $${{{K_p}} \over {{K_c}}}$$ is equal to :

The equilibrium constant for the reaction N₂(g) + O₂(g) $$\leftrightharpoons$$ 2NO(g) at temperature T is 4 $$\times$$ 10^-4. The value of K_c for the reaction NO(g) $$\leftrightharpoons$$ $$1 \over 2$$N₂ (g) + $$1 \over 2$$O₂ (g) at the same temperature is :

For the reaction equilibrium
N₂O₄ (g) $$\leftrightharpoons$$ 2NO₂ (g)
the concentrations of N₂O₄ and NO₂ at equilibrium are 4.8 $$\times$$ 10^-2 and 1.2 $$\times$$ 10^-2 mol L^-1 respectively. The value of K_c for the reaction is