In the thermal dissociation fo `PCl_(5).` the partical pressure in the gaseous equlibrium mixture is 1.0 atmosphere when half of `PCl_(5)` is found to dissociate. The equlibrium constant of the reaction `(K_(p))` in atomosphere is

Options

A. `0.25 `
B. ` 0.50`
C. `1.00 `
D. `0.3`

Answer

D

Explanation

`PCl_(5) hArr PCl_(3) + Cl_2`
`{:("Initial conc.",1,0,0),("At equilibrium",0.5,0.5,0.5):}`
`K_p = (Px^2)/((1-x^2))=(1xx0.5 xx0.5 )/([1-(0.5)^2])=(0.5 xx0.5)/(0.75)=1/3 =0.3`