an aqueous solution was prepared by dissolving 1438.0g of a nonelectrolyte in 469.0g of water at 25*c. the Vapor pressure of the resulting solution was found to be 20.5 torr. what is the molar mass of the unknown compound? the vapor pressure of the water at 25*c is 23.76torr.

Answer 1

delta Psoln = Xsolute*P^o_H2O
23.76-20.5 = Xsolute*Psolvent
Solve for Xsolute.
Then
nsolute/(n solute + n H2O) = Xsolute
n H2O = 469/molar mass H2O.
Solve for n solute, then
n = grams/molar mass and rearrange to
molar mass = grams/n. Solve for molar mass.