1 / 14

Colligative Properties

Colligative Properties . Learning Target: What are the four colligative properties of solutions? Determine the boiling point elevation and freezing point depression of a solution. Main Idea. Colligative properties depend on the number of solute particles in a solution.

Download Presentation

Colligative Properties

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Colligative Properties Learning Target: What are the four colligative properties of solutions? Determine the boiling point elevation and freezing point depression of a solution.

  2. Main Idea • Colligative properties depend on the number of solute particles in a solution.

  3. Colligative Property • Colligative propertiesare physical properties of solutions that are affected by the number of particles but not by the identity of dissolved solute particles. • Ionic compounds are electrolytes because they dissociate in water to form a solution that conducts electricity. • Some molecular compounds are also electrolytes.

  4. 4 colligative properties: • Vapor Pressure Reduction • Boiling Point Elevation • Freezing point depression • Osmotic Pressure

  5. Vapor Pressure Reduction • Molecules of nonvolite solute take up space, thus preventing some solvent molecules to vaporize. • Condensation continues at the same rate, but vaporization slows down. • Since condensation > vaporization, vapor pressure is reduced.

  6. Boiling Point Elevation (ΔTb) • Adding a nonvolite solute, reduces vapor pressure, more energy is needed to make the solutions boil, raising the boiling point. • Boiling point elevation = BP of the solution - BP of the solvent. • Directly proportional to the number of solute molecules.

  7. Boiling Point Elevation

  8. Boiling Point Elevation (ΔTb) • ΔTb = Kbm • Kb = boiling point elevation constant • m= molality

  9. Freezing Point Depression (ΔTf) • The ability of a solute to lower freezing point of the solution. • Directly proportional to the molality of the solute. • ΔTf = Kfm • Kf = freezing point depression constant • m= molality

  10. Osmotic Pressure • Osmosis: The movement of water molecules from high water concentration to low water concentration. • Osmotic pressureis the amount of additional pressure caused by water molecules that moved into the concentrated solution.

  11. Osmotic Pressure & types of solutions • Isotonic concentration: solute concentration is the same on both sides of the membrane. • Hypertonic: higher solute concentration than the solution • Hypotonic: lower solute concentration than the solution

  12. Examples • 1. How much will the boiling point of water be elevated if 100. g of sucrose (C12H22O11) is added to 500.g of water? Kb for water is 0.52 °C/m. • ΔTb = kbx m

  13. Example 2 • What is the freezing point depression when 153g of bromine is added to 1000. g of benzene?

More Related