In equation (2), the vapor pressure of the solute in solution is given by , the mole fraction of the solute in solution is given by , and the vapor pressure of the pure solute is given by Equation (2) is only relevant if the solute is volatile (if it forms a vapor).
Example:
15.0g of calcium carbonate is dissolved in 250g of water. If the water has a temperature of 100¬°C, what is the resulting vapor pressure of the water in solution?
Raoult's law (equation 1) gives the answer to this problem once the mole fraction has been calculated. Since the vapor pressure of the solvent is needed, the mole fraction of the solvent must be found. First, the number of moles of both solute and solvent are found.
