CHM120H5 Lecture 7: intermolecular forces part 7
Vapor Pressure of Solutions
•The vapor pressure of a solvent above a solution is lower than
the vapor pressure of the pure solvent
–the solute particles replace some of the solvent molecules at
the surface
The pure solvent establishes a liquid vapor equilibrium
Raoult’s Law
•The vapor pressure of a volatile solvent above a solution is
equal to its normal vapor pressure, P°, multiplied by its mole
fraction in the solution
Psolvent in solution = solvent∙P°
–because the mole fraction is always less than 1, the vapor
pressure of the solvent in solution will always be less than the
vapor pressure of the pure solvent
•The vapor pressure of a solvent in a solution is always lower
than the vapor pressure of the pure solvent
•The vapor pressure of the solution is directly proportional to
the amount of the solvent in the solution
find more resources at oneclass.com
find more resources at oneclass.com