Question

The vapour density of `PCl_(5)` at `43K` is is found to be `70.2`. Find the degree of dissociation of `PCl_(5)` at this temperature.

Answer 1

Correct Answer - D
Theroretical vapour density of `PCl_(5)` is
`D=("molecular weight of" PCl_(5))/(2)`
`=(31+5xx35.5)/(2)`
`=208.5/2=104.25`
Observed vapour density is, `d=70.2`
`:.` Degree of dissociation `(alpha)=(104.25-70.2)/70.2=0.485`