Question from chemical and ionic equilibrium:

A vessel at 1000K has CO₂ at 0.5 atm pressure. Some of the CO₂ is converted into CO on the addition of graphite. If the total pressure at equilibrium is 0.8atm, find the value of K_p

Please Help............

CO2 +C ------2COinitial presasure=.5atmfinal pressure on addition of graphiteCO2=.5-XCO=2Xtotal pressure at equilibrium=.5+xbut the total pressure at equilibrium= .8atm,5+x=.8atmx=.3atmthe value of reaction constant,K=[CO]^2/[CO2]=.6^2/.2=1.8  RegardsArun (askIITians forum expert)