Unit 6: Solutions and Solubility

1. Unit 6: Solutions and Solubility Day 4 Colligative Property Calculations

2. Unit 6: Solutions and Solubility 1. Decrease in Vapor Pressure - Raoult’s Law describes the relationship between the vapor pressure of the pure solvent and vapor pressure of the solution - What is the formula a when does it work? Example: If 651 grams of ethylene glycol (HOCH2CH2OH) is dissolved in 1.50 kg of water. What is the vapor pressure of the water at 90oC? Assume ideal behavior for the solution. VP of water at 90oC is 525.8 mmHg

3. Unit 6: Solutions and Solubility 2. Boiling Point Elevation - The formula and it’s use

4. Unit 6: Solutions and Solubility 2. Boiling Point Elevation - The formula and it’s use Example: What is the boiling point of a solution containing 0.144 grams of Eugenol, C10H12O2, dissolved in 10.0 grams of benzene? (kbp for benzene = 2.53 oC/m) (Normal bp=80.1oC) 3. Freezing Point Depression - The formula and it’s use Example: Calculate the freezing point of 525 g of water that contains 25.0 g of NaCl. Assume the van’t Hoff factor is 1.85 for NaCl at this concentration. (kfp for water = -1.86 oC/m)

5. Unit 6: Solutions and Solubility Suspensions Sand in water … Temporary, heterogeneous mixture, settling occurs over time

6. Unit 6: Solutions and Solubility Suspensions Sand in water … Temporary, heterogeneous mixture, settling occurs over time Colloids An intermediate state between solutions and suspensions

7. Unit 6: Solutions and Solubility Colloids -An intermediate state between solutions and suspensions -Often one molecule is used to “more permanently” suspend another, creating a homogeneous mixture that is not technically a solution. 1. Emulsions - Liquid dispersed in another liquid - Typically two immiscible liquids (oil and water) - Emulsifying agents keep the layers from separating out.

8. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Polar head Non-polar tails

9. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

10. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

11. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

12. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

13. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

14. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

15. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

16. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

17. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

18. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

19. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

20. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

21. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

22. Carriers of hydrophobic compounds Oil • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

23. Carriers of hydrophobic compounds Oil • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood.

24. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Oil

25. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Oil

26. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Oil

27. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Oil

28. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Oil

29. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Oil

30. Carriers of hydrophobic compounds • Hydrophobic compounds attach to hydrophobic tails. • The hydrophillic head allows them to be transported through the blood. Oil This is how fats, oils and cholesterol get moved through your bodily fluids!

31. Unit 6: Solutions and Solubility Colloids -An intermediate state between solutions and suspensions -Often one molecule is used to “more permanently” suspend another, creating a homogeneous mixture that is not technically a solution. 2. Aerosols (Solid aerosols) - Liquid (or solids) dispersed in a gas - Clouds, smoke, fog, hair spray - Particles must be very small to remain dispersed

32. Unit 6: Solutions and Solubility Colloids -An intermediate state between solutions and suspensions -Often one molecule is used to “more permanently” suspend another, creating a homogeneous mixture that is not technically a solution. 3. Foams - Gas dispersed in a liquid - Whipped cream, shaving cream - Pockets of gas are “trapped” within the liquid

33. Unit 6: Solutions and Solubility Colloids -An intermediate state between solutions and suspensions -Often one molecule is used to “more permanently” suspend another, creating a homogeneous mixture that is not technically a solution. 4. Sol - Solid dispersed in liquid - Ink, blood, paints, ferrofluids - Solid particles usually very small, can be suspended in the liquid by other molecules (similar to emulsions) Ferrofluids

34. Unit 6: Solutions and Solubility Colloids -An intermediate state between solutions and suspensions -Often one molecule is used to “more permanently” suspend another, creating a homogeneous mixture that is not technically a solution. 5. Gel - Liquid dispersed in a solid - Gelatin and jelly - Mostly composed of liquid, but behave as a solid because of a 3-D, cross-linked solid structure within the substance.

35. Unit 6: Solutions and Solubility Colloids -An intermediate state between solutions and suspensions -Often one molecule is used to “more permanently” suspend another, creating a homogeneous mixture that is not technically a solution. Things to notice … Emulsions