The vapour pressure of benzene and pure toluene at 70°C are 500 mm and 200 mm Hg respectively.If they form an ideal solution what is the mole fraction of benzene in a mixture boiling at 70° C at a total pressure of 380 mm Hg ?

Question

The vapour pressure of benzene and pure toluene at 70°C are 500 mm and 200 mm Hg respectively.If they form an ideal solution what is the mole fraction of benzene in a mixture boiling at 70° C at a total pressure of 380 mm Hg ? (A) 0.20 (B) 0.40 (C) 0.60 (D) 0.80

Tardigrade Admin · Accepted Answer

Let mol. fraction of Benzene is x ∴ 380 = x × 500 + (1 - x ) 200 or x = 0.6.

Q. The vapour pressure of benzene and pure toluene at 70 $^{\circ}$ C are 500 mm and 200 mm Hg respectively.If they form an ideal solution what is the mole fraction of benzene in a mixture boiling at 70 $^{\circ}$ C at a total pressure of 380 mm Hg ?

0.20

0.40

0.60

0.80

Let mol. fraction of Benzene is $x$
$∴$ 380 = $x \times 500 + (1 - x) 200$ or $x$ = 0.6.

Q. The vapour pressure of benzene and pure toluene at 70∘C are 500 mm and 200 mm Hg respectively.If they form an ideal solution what is the mole fraction of benzene in a mixture boiling at 70∘ C at a total pressure of 380 mm Hg ?