A vessel at `1000 K` contains carbon dioxide with a pressure of `0.5 atm`. Some of the carbon dioxide is converted to carbon monoxide on addition of graphite. Calculate the value of `K_(p)` if total pressure at equilibrium is `0.8 atm`.

Explanation

The reaction taking place is :
`CO_(2)(g) + C(s) hArr 2CO(g)`
Suppose that the decrease in pressure of `CO_(2)(g)` after taking part in the reaction =p atm.
Then increase in pressure of CO(g) =2p atm
The partial pressure in the equilibrium mixture are :

Total pressure =(0.5 -p + 2p) =(0.5 +p) atm
But the final pressure =0.8 atm (given)
0.5 +p =0.8 or p = 0.8 -0.5 =0.3 atm
According to the equation `K_(p) =(P_(CO(g))^(2))/(P_(CO_(2)(g)))=((0.6 " atm ") xx (0.6 " atm "))/((0.5 " atm " -0.3 " atm "))`
`=(0.6 " atm " xx 0.6 " atm ")/(0.2 " atm ") =1.8 atm`