A vessel at 1000K contains carbon dioxide at 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, if the total pressure at equilibrium is 0.8atm.

Explanation

`CO_(2)+C_(("graphite")) Leftrightarrow 2CO`
Let the decrease in pressure of `CO_2` after reaction =p atm
Then, increase in pressure due to CO after reaction =2p atom
Final total pressure =(0.5-p) +2p =0.8 atm
p=0.3 atm
Thus after reaction, `p_(CO_(2))=0.5-0.3=0.2 atm`
`p_(CO)=2p=2 xx 0.3=0.6 atm`
`rArr K=(p_(CO)^2)/(p_(CO_(2)))=((0.6)^2)/((0.2))=1.8 atm`