At 258°C, Kp = 2.9 10-3 atm3 for the following reaction. NH4OCONH2(s) 2 NH3(g) + CO2(g)?

Question

In an experiment carried out at 258°C, a certain amount of NH4OCONH2 is placed in an evacuated rigid container and allowed to come to equilibrium. Calculate the total pressure in the container at equilibrium.

Answer 1

NH4OCONH2(s) <==> 2 NH3(g) + CO2(g)
Let the CO2(g) pressure at equilibrium to be X atm, thus NH3(g) pressure at equilibrium is 2X atm.
Kp = 2.9x10^(-3) atm^3 = 4X^3
X = 0.0898 atm.
Hence the total pressure in the container at equilibrium is 3X = 0.270 atm.