A container is filled with CO2(g) and heated to 1000K. The gas pressure at this temperature is 0.50 atm. Graphite (C) is then added to the container and some of the CO2 is converted to CO according to the reaction below. The final equilibrium total gas pressure in the flask is 0.80 atm. Calculate Kp at 1000K for this system.

Question

A container is filled with CO2(g) and heated to 1000K.  The gas pressure at this temperature is 0.50 atm.  Graphite (C) is then added to the container and some of the CO2 is converted to CO according to the reaction below.  The final equilibrium total gas pressure in the flask is 0.80 atm.  Calculate Kp at 1000K for this system.

CO2(g) + C(s) <--> 2CO(g)

Don't know how to set it up!

DrBob222 · Answer

I would approach it this way.
........CO2 + C ==> 2CO2
I.......0.5..solid....0
C.......-x...........2x
E......0.5-x.........2x
You know that0.5-x + 2x = 0.8
Solve for x, then pCO2 and pCO2 and plug those into the Kp expression and solve for Kp.

Nat · Answer

Thanks got it!