What is the vapor pressure above a solution prepared by dissolving 0.500 mol of a nonvolatile solute in 275 g of hexane (86.18 g/mol)at 49.6°C? P°hexane = 400.0 torr at 49.6°C.
A)54 torr
B)154 torr
C)246 torr
D)346 torr
E)400.torr

Question

Quizplus · Accepted Answer

The vapor pressure of the solution is calculated using Raoult's Law: P_solution = X_solvent * P°_solvent. First, calculate the moles of hexane: 275 g / 86.18 g/mol = 3.19 mol. The mole fraction of hexane is 3.19 / (3.19 + 0.500) = 0.864. Then, P_solution = 0.864 * 400.0 torr = 346 torr.

What Is the Vapor Pressure Above a Solution Prepared by Dissolving