In the reaction : C(s)+CO2(g)⇌2CO(g), the equilibrium pressure is 6 atm. If 50% of CO2 reacts, then Kp of the reaction is _______.
Let the initial pressure of CO2 be P atm. Since 50% is dissociated, its equilibrium pressure will be 0.5 P atm. The equilibrium pressure of CO will be P atm.
Total pressure will be 0.5P+P=1.5P=6atm
P=4atm
Thus, the equilibrium pressures of CO2 and CO are 2 atm and 4 atm respectively.
The equilibrium constant expression is Kp=P2COPCO2=422=8.