Vapor Pressure and Raoult's Law

[Qube]

Homework Statement

The vapor pressure of pure water at 45 degrees C is 71.9 mm Hg. What is the vapor pressure when 18g of sucrose (MM = 342.3g/mol) is added to 82g of water?

Homework Equations

VP of solution = mole fraction of solvent * VP of pure solvent

The Attempt at a Solution

82g of water / (18g/mol) = 4.555... moles of water.

18g of sucrose / (342.3g/mol) = 0.0525 moles of water

Mole fraction of solvent (water) = 0.988.

0.988 * 71.9 mm Hg = new vapor pressure of 71.1 mm Hg.

Is my work correct? It's 3 AM here and I'm just a bit concerned about how accurate I am in doing these practice problems.

 

[nate808]

I can confirm that your work is correct. The equation you used is the correct one for calculating the vapor pressure of a solution, and your calculations are accurate. It's always good to double check your work, especially when it's late at night and you're feeling tired. Keep up the good work!