The vapour pressure of a solution of the liquids A `(p^(@)=80m m Hg and X _(A) =0.4) and (p^(@) =120 mn Hg and X _(B) =0.6)` is found to be 100 mm Hg. It shows that the solution exhibits

Options

A. positive deviation from ideal behaviour
B. negative deviation from ideal behaviour
C. ideal behaviour
D. positive deviation for lower cone. and negative for higher cone.

Answer

B

Explanation

`p _("total") = p_(A)^(@)x x _(A) +p_(B)^(@) x x_(B)`
`=80.0 x0.4 +120.0 x0.6 =10` 4m m Hg
Thte observed ` P _("total")` is 100 mm Hg which is less then 104 mm Hg. Hence the solutio shows negative dcviation.