Answer:
A. 0525.
B. 0.3483 atm.
C. 0.3890.
Explanation:
A.
Molar mass of Benzene =
(12*6) + (1*6)
= 78 g/mol.
Number of moles of Benzene = mass/molar mass
= 50/78
= 0.641 moles.
Molar mass of n-hexane =
(12*6) + (1*14)
= 86 g/mol.
Number of moles of n-hexane = mass/molar mass
= 50/86
= 0.581 moles.
Total moles of the solution = number of moles of Benzene + number of moles of n-hexane
= 0.641 + 0.581
= 1.222 moles
Mole fraction is the number of moles of a particular substance in a solution divided by the total number of moles of substances in the solution.
Mole fraction of Benzene = 0.641/1.222
= 0.525.
B.
Vapour Pressure of a solution is the amount of pressure that the vapour exert on the liquid solvent when they are in equilibrium and at a certain temperature.
Uaing Raouit's law and Dalton's law,
Raoult's law states that the the partial pressure of a solution is directly proportional to the mole fraction of the solute component.
Dalton's law states that the total pressure of a solution is the sum of its individual partial pressure.
Uaing Dalton's law,
Psol = Pbenzene + Pn-hexane
= 0.1355 + 0.2128
= 0.3483 atm
C.
Using Raoult's equation, Mole fraction of Benzene = P°benzene/Psol
= 0.1355/0.3483
= 0.3890
