A vessel of '1000 K' contains 'CO_2', with a pressure of '0.5 atm .' Some of the 'CO_2' converted into 'CO' on the addition of graphite. The value of 'K' if the total pressure at equilibrium is '0.8 atm'. is:

Options

A. 0.36 atm
B. 6.8 atm
C. 1.8 atm
D. 3.2 atm

Answer

C

Explanation

`{:(,CO_(2)(g)+,C(s),hArr,2CO(g)),("Initial","0.5 atm",,,"0 atm"),("At equilibrium","(0.5-x)",,,"2x atm"):}`
At equilibrium, the pressure is 0.8 atm
`P_("total") = P_(CO_(2)) + P_(CO)`
`0.8 = (0.5-x) + 2x = 0.5 + x` or `x = 0.3` atm
Applying the law of mass action , `K_(p) = ((p_(CO))^(2))/(p_(CO_(2))) = ((2 xx 0.3)^(2))/(0.2) = (0.36)/(0.2) = 1.8` atm