You can determine the molar of an unknown solute from the boiling point elevation. When you do an experiment, add a certain known amount of the unknown compound to a solvent, say water. Then, determine the boiling point of the solution. The working equations would be the following:
Temp difference = Boiling pt of solution - Boiling point of pure solvent
Moles solute = (Temp difference)(Mass of solvent)/(Ebullioscopic constant of water)
Molar Mass = Mass of solute/Moles solute
The boiling point of water is 100°C,while the ebullioscopic constant is 0.512 °C/molal.
