1. colligative property- depends on the # of particles dissolved in a given amount of solvent *ionic produces greater result than molecular because they dissociate Ex: vapor pressure and freezing point lowering boiling point and osmotic pressure increase

2. ex: How many particles? CaCℓ 2 3 NaCℓ 2 C 6 H 12 O 6 1

3. -vapor pressure lowers when solute is added WHY? -IMF of particles makes it harder to escape to gaseous phase, lowering vapor pressure

4. ideal solution- obeys Raoult’s Law -implies total uniformity of interaction -all molecules influence each other the same way (sol-sol, solv-solv, solv-sol are indistinguishable) *real solutions are more like ideal solutions when solute conc. is low and solute and solvent have similar sizes and take part in similar types of intermolecular attractions

5. Boiling point Elevation -bp of solution is higher than that of the pure solvent *adding solute lowers vapor pressure and a higher temp is needed to get to 1 atm for normal bp -page 533

6. Freezing Point Depression -fp of solution is lower than that of the pure solvent *adding solute lowers vapor pressure so a lower temp is needed to freeze at 1atm -page 534

7. page 540 A Closer Look