Phosgene (COCl2) is a poisonous gas that dissociates at high temperature into two other poisonous gases, carbon monoxide and chlorine with equilibrium constant Kp = 0.0041 at 600 K. Find the equilibrium composition of the system after 0.124 atm of COCl2 is allowed to reach equilibrium at this temperature in a sealed reaction vessel.

Answer 1

Have you ever heard of ICE charts?

http://www.chem.purdue.edu/gchelp/howtosolveit/Equilibrium/ICEchart.htm