Answer to Question #266498 in General Chemistry for Trish

Question

An ideal solution contains 92. 1 g of glycerin, C3H5(OH)3, and 184.4 g of ethanol, C2H5OH, at 40 oC. The vapor pressure of pure ethanol is 0.178 atm at 40 oC. What is the molality of the solution? What is the vapor pressure of a solution?

Answer 1

Vapor pressure of pure ethanol = p = 0.178 atm

Vapor pressure of the glycerin solution = P_s

Mass of glycerin = 92.1 g

Moles of glycerin =

Mass of ethanol = 184.4 g

Moles of ethanol =

Relative lowering in the vapor pressure of the solution with non volatile solute is equal to the mole fraction of solute.

The vapor pressure of the solution is 0.142 atm.

Weight percentage of glycerin is

: