Step-by-step explanation:
(a) The given data is as follows.
= 511 torr, = 150 torr
Mass of pentane = volume × density
=
= 1265.75 g
Mass of hexane = volume × density
=
= 2279.7 g
Now, we will calculate the moles of both pentane and hexane as follows.
No. of moles of pentane =
=
= 17.58 mol
No. of moles of hexane =
=
= 26.51 mol
Tota number of moles = 17.58 mol + 26.51 mol
= 44.09 mol
Mole fraction of pentane () =
=
= 0.39
Mole fraction of hexane () =
=
= 0.60
So, we will calculate the vapor pressure of the solution as follows.
where, = mole fraction of solution 1
= partial pressure of pure solvent of solution 1
= mole fraction of solution 2
= partial pressure of pure solvent of solution 2
=
= (199.29 + 90) torr
= 289.29 torr
Therefore, vapor pressure of this solution is 289.29 torr.
(b) Mole fraction of pentane in the vapor that is in equilibrium with this solution is calculated as follows.
=
=
=
Hence, mole fraction of pentane in the vapor that is in equilibrium with this solution is .