To calculate freezing point and boiling point;
1. Convert grams of solute to moles of solute and then molality of the solution.
2. ID the solute to number of particles. Ex: CaCl 2= 3 particles
C6H12O6= 1 particle
3. Multiply the number of particles by the molality calculated #1 to get the new molality
4. Plug into formula:
a. Freezing
delta t = Kf(of solvent) m (new molality)
b. Boiling
delta t = Kb (of solvent) m (new molality)
5. Old freezing point – delta t = new freezing point
6. Old boiling point + delta t = new boiling point
When a solute is added to a pure solvent the freezing point is lowered and the boiling point of the
solvent is elevated.
To calculate molar mass work backwards. Step 5 or 6 goes step 4, and step 4 goes to three. In step 3
where you multiply by particles you will divide.