# Raoult's Law

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Raoult's law is the vapor pressure of a solution is changed by the addition of a solute.

## Raoult's Law Formula

 $$\large{ p_s = x_s\; p°_s }$$

### Where:

 Units English Metric $$\large{ p_s }$$ = vapor pressure of the solution $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$ $$\large{ x_s }$$ = mole fraction of the solvent in the solution $$\large{dimensionless}$$ $$\large{ p°_s }$$ = vapor pressure of the pure solvent at standard conditions $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$