A mixture contains 1 mole of volatile liquid A `("P"_("A")^(0)=80"mm Hg").` and 3 moles of volatile liquid B `("P"_("A")^(0)=80"mm Hg").` If solution behaves ideally, the total vapour pressure of the distillate is

Options

A. 85 mm Hg
B. 85.88 mm Hg
C. 90 mmHg
D. 92 mm Hg

Answer

B

Explanation

`"x"_("A")=1/4,"x"_("B")=3/4`
`"y"_("A")=("x"_("A")"P"_("A")^(0))/("x"_("A")("P"_("A")^(0)-"P"_("B")^(0))+"P"_("B"))`
`"y"_("A")=(1/4xx100)/(1/4(100-80)+80)`
`"y"_("A")=5/17`
`"y"_("B")=12/17`
`"P"_("distillate")="y"_("A")("P"_("A")^(0)-"P"_("B")^(0))+"P"_("B")^(0)`
`=5/17(100-80)+80=85.88`