2.0 mole of`PCl_(5)` were nttoducedd in a vessel of 5.0 L capacity of a particular temperature At equilibrium, `PCl_(5)` was found to be 35 % dissociated into `PCl_(3)and Cl_(2)` the value of `K_(c)` for the reaction
`PCl_(3)(g)+Cl_(2)(g)hArrPCl_(5)(g)`

Options

A. 1.89
B. 0.377
C. 0.75
D. 0.075

Answer

D

Explanation

Moles of `PCl_(5)` dissociated `=(2xx35)/(100)=0.7`
Moles of `PCl_(5)` left undissociated `=2-0.7=1.3 mol rArr [PCl_(5)]=(1.3)/(5)M, [PCl_(3)]=(0.7)/(5)M, [Cl_(2)]=(0.7)/(5)M`
`K_(c)=([PCl_(3)][Cl_(2)])/([PCl_(5)])=(((0.7)/(5))((0.7)/(5)))/(((1.3)/(5)))=0.075`