Question

Question 14 Ammonia and oxygen react to form nitrogen monoxide and water, like this: (g)(g)(g)(g) Write the pressure equilibrium constant expression for this reaction.

Answer 1

Answer:

$Kp = \frac{(pNO)^4*p(H_2O)^6}{(pNH_3)^4*(pO_2)^5}$

Explanation:

The reaction is:

4NH₃(g) + 5O₂(g) ⇄ 4NO(g) + 6H₂O(g)

The equilibrium is achieved when the velocity of the formation of the products is equal to the velocity of the formation of the reactants, and then the concentrations and the partial pressures remain constant.

The equilibrium can be characterized by the equilibrium constant, which is a factor of the activity of each component. The solids and pure liquids have activity equal to 1, and so, they are not placed in the expression of the constant.

The other substances may have its activity substituted to the concentration, or the partial pressure (only gases). So, in the first case the constant will be the concentration equilibrium constant (Kc), and the second case the pressure equilibrium constant (Kp).

The constant is the ratio of the multiplication of the concentration (or pressure) of the products by the multiplication (or pressure) of the products. Each of the concentration (or pressure) is elevated by the coefficient of the substance.

So, for the reaction given:

$Kp = \frac{(pNO)^4*p(H_2O)^6}{(pNH_3)^4*(pO_2)^5}$