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`.

Options

A. `1.8` atm
B. 3 atm
C. `0.3` atm
D. `0.18` atm

Answer

A

Explanation

`{:(,CO_(2)(g),+,C(s),hArr,2CO(g)),("Initial",,,0.5atm,,,__),("At equilibrium",,,0.5-p,,2patm):}`
This is a case of heterogeneous equilibrium. C(s) being solid is not considered. Total pressure of `CO_(2)` and CO gases.
`P_(CO_(2)) + P_(CC) = P_(total)`
`0.5- (p+2p) = 0.8, p=0.3` atm
`:.` `P_(CO_(2)) = 0.5 - 0.3 = 0.2` atm
`P_(CO) = 2p = 0.6` atm
`K_(p) = (P^(2)CO)/(PCO_(2)) = (0.6xx0.6)/(0.2) = 1.8` atm