Final answer:
The vapor pressure of a benzene solution, determine the mole fraction of benzene using the weights and molar masses of biphenyl and benzene, and then apply Raoult's Law.
Step-by-step explanation:
The question refers to the calculation of the vapor pressure of a solution created by dissolving biphenyl (C12H10) in benzene (C6H6). According to Raoult's Law, the vapor pressure of a solution is proportional to the mole fraction of the solvent times the vapor pressure of the pure solvent.
Therefore, to find the vapor pressure of the benzene solution, we need to calculate the mole fraction of benzene based on the weights of biphenyl and benzene provided and the molar masses of both compounds.
First, we calculate the moles of benzene and biphenyl:
- Molar mass of biphenyl (C12H10) = 154 g/mol (approx.)
- Molar mass of benzene (C6H6) = 78 g/mol
- So, moles of biphenyl = 0.0503 kg / 154 g/mol
- Moles of benzene = 350 mL / 0.789 g/mL (density of benzene at 20 ℃) / 78 g/mol
Next, we calculate the mole fraction of benzene (Xbenzene):
- Xbenzene = moles of benzene / (moles of benzene + moles of biphenyl)
Finally, we apply Raoult's Law to get the vapor pressure of the solution (Psolution):
- Psolution = Xbenzene * vapor pressure of pure benzene
Note that in this example, we do not give the exact numeric answer; instead, we describe the method of how to calculate it.