Finding Total Pressure

[mact14a 1D]

Hi! How would you find total pressure when given only the reaction equation (ex. (s) ⇌ (s) + (g) + (g)), Kp, and T? I know total pressure is equal to the sum of the partial pressures but I am not sure how to find the partial pressures from there and I am unsure of the role that solids play in finding partial pressure. Thanks in advance!

[mlomas2004]

To find the total pressure, you'll need to first calculate the partial pressures of the gases involved using the given equilibrium constant (Kp) and the reaction equation. Since solids don't exert pressure, they're not included in the partial pressure calculation. You can use the expression for Kp to determine the equilibrium partial pressures of the gases, then sum them up to find the total pressure.

[Patel Kardoukian 1F]

You would find partial pressures by either using PV=nRT, or using mole fractions, which would be the formula partial pressure=total pressure x mole fraction. You could also use the ICE chart if the Kp is given. It all depends on what information you are given. Now looking into the solids in the equation, the ICE table and Kp formula would just disregard the solids, so it would be ((s)(s))/1.