Equilibrium Pressure Calculation for the Reaction NH4COONH2(s) ⇌ 2NH3(g) + CO2(g)

To determine the equilibrium pressure (Kp) for the reaction NH4COONH2(s) ⇌ 2NH3(g) + CO2(g), we need to consider the balanced equation and apply the ideal gas law.

1. Balanced Equation:
The balanced equation for the reaction is as follows:
NH4COONH2(s) ⇌ 2NH3(g) + CO2(g)

2. Equilibrium Expression:
The equilibrium expression for a reaction in terms of partial pressures is given by:
Kp = (P(NH3)^2 * P(CO2)) / P(NH4COONH2)

3. Determining Equilibrium Pressure:
Given that the equilibrium pressure is 3 atm, we can assume that the partial pressures of NH3 and CO2 are also 3 atm each. However, we need to determine the partial pressure of NH4COONH2.

Since NH4COONH2 is a solid, its concentration does not contribute to the equilibrium expression. Therefore, we can assume the partial pressure of NH4COONH2 to be 1 atm.

4. Calculation of Kp:
Substituting the given partial pressures into the equilibrium expression, we get:
Kp = (3^2 * 3) / 1
Kp = 27

Therefore, the equilibrium pressure (Kp) for the reaction NH4COONH2(s) ⇌ 2NH3(g) + CO2(g) is 27.

Explanation:
The equilibrium expression represents the ratio of the product pressures to the reactant pressure at equilibrium. It allows us to quantitatively measure the extent of the reaction. In this case, the equilibrium pressure (Kp) is calculated using the partial pressures of NH3, CO2, and NH4COONH2.

Since NH4COONH2 is in the solid state, its concentration remains constant and does not affect the equilibrium expression. Therefore, we assume its partial pressure to be 1 atm.

By substituting the given partial pressures into the equilibrium expression, we can calculate the value of Kp. In this example, the equilibrium pressure is given as 3 atm, and assuming the partial pressures of NH3 and CO2 to be the same, we find that Kp is equal to 27.

This value of Kp indicates that the forward reaction is favored at equilibrium, as the product pressures are much higher than the reactant pressure.