For the dissociation of `PCl_(5)` into `PCl_(3)` and `Cl_(2)` in gaseous phase reaction , if d is the observed vapour density and D the theoretical vapour density with `'alpha'` as degree of dissociation ,variaton of D/d with `'alpha'` is given by ?

Options

A.
B.
C.
D.

Answer

B

Explanation

`PCl_(5)hArr PCl_(3)+Cl_(2)`
Here `y=2`
`:. `Degree of dissociation,
`x=(D-d)/(d(2-1))`
`x=(D-d)/(d)`
`x=(D)/(d)-1`
If graph between x (along Y-axis) and `(D)/(d)` (along X-axis) is a straight line with slope, `m=1` and intercepts on Y-axis , `c=-1`
`(y=mx+c` type )

Thus, choice (B) is correct.