A solution is prepared by adding 30.00 g of lactose (milk sugar)to 110.0 g of water at 55° The partial pressure of water above the solution is ________ torr.The vapor pressure of pure water at 55°C is 118.0 torr.The molar mass of lactose is 342.3 g/mol.
A) 1.670
B) 94.1
C) 169.4
D) 116.3
E) 92.7

Question

Quizplus · Accepted Answer

The vapor pressure of the solution can be calculated using Raoult's Law: P_solution = X_solvent * P_pure. First, calculate the moles of lactose (30.00 g / 342.3 g/mol) and water (110.0 g / 18.015 g/mol). Then, find the mole fraction of water (X_solvent). Finally, multiply the mole fraction by the vapor pressure of pure water (118.0 torr) to find the vapor pressure of the solution, which is approximately 116.3 torr.

A Solution Is Prepared by Adding 30