1. Chemistry Mrs. Nunez

2. Solution - Solution - homogeneous mixture Solvent Solvent - present in greater amount Solute Solute - substance being dissolved

3. Solvation the process of dissolving solute particles are separated and pulled into solution solute particles are surrounded by solvent particles

4. Strong Electrolyte Non- Electrolyte solute exists as ions only - + salt - + sugar solute exists as molecules only - + acetic acid Weak Electrolyte solute exists as ions and molecules DISSOCIATIONIONIZATION

5. Dissociation separation of an ionic solid into aqueous ions NaCl(s)  Na + (aq) + Cl – (aq)

6. Ionization breaking apart of some polar molecules into aqueous ions HNO 3 (aq) + H 2 O(l)  H 3 O + (aq) + NO 3 – (aq)

7. Molecular Solvation molecules stay intact C 6 H 12 O 6 (s)  C 6 H 12 O 6 (aq)

8. NONPOLAR POLAR “Like Dissolves Like” “Like Dissolves Like”

9. C. Johannesson Soap/Detergent Soap/Detergent polar “head” with long nonpolar “tail” dissolves nonpolar grease in polar water

10. Solubility SATURATED SOLUTION no more solute dissolves UNSATURATED SOLUTION more solute dissolves SUPERSATURATED SOLUTION becomes unstable, crystals form concentration

11. Solubility maximum grams of solute that will dissolve in 100 g of solvent at a given temperature varies with temp based on a saturated soln Factors determining rate of solution... 1. stirring (agitation) 2. surface area the dissolving particles 3. temperature

12. C. Johannesson C. Solubility Solids are more soluble at... Solids are more soluble at... high temperatures.  Gases are more soluble at... low temperatures & high pressures (Henry’s Law). EX: nitrogen narcosis, the “bends,” soda

13. Solubility Solubility Curve Solubility Curve shows the dependence of solubility on temperature

14. Solids tend to dissolve best when: They are heated They are stirred Crushed into smaller particles Gases tend to dissolve best when: The solution is cold The pressure is high

15. Liquids Miscible means that two liquids can dissolve in each other water and antifreeze water and ethanol Partially miscible- slightly water and ether Immiscible means they can’t oil and vinegar

16. Gases in liquids... Henry’s Law - says the solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid think of a bottle of soda pop, removing the lid releases pressure Equation: S 1 S 2 P 1 P 2 Sample 16.1, page 477 =

17. Concentration The amount of solute in a solution. Describing Concentration % by mass - medicated creams % by volume - rubbing alcohol ppm, ppb - water contaminants molarity - used by chemists molality - used by chemists

18. Concentrated vs. Dilute Lots of solute, in a small amount of solvent. Small amount of solute in a large amount of solvent. Notice how dark the solutions appears. Notice how light the solution appears. CONCENTRATEDDILUTE

19. A. Molarity Concentration of a solution. total combined volume substance being dissolved

20. Molarity 2M HCl What does this mean?

21. Molarity Calculations Find the molarity of a 250 mL solution containing 10.0 g of NaF. 10.0 g 1 mol 41.99 g = 0.238 mol NaF 0.238 mol 0.25 L M == 0.95M NaF

22. B. Molality mass of solvent only 1 kg water = 1 L water

23. Molality Find the molality of a solution containing 75 g of MgCl 2 in 250 mL of water. 75 g MgCl 2 1 mol MgCl 2 95.21 g MgCl 2 = 3.2 m MgCl 2 0.25 kg water

24. C. Dilution Preparation of a desired solution by adding water to a concentrate. Moles of solute remain the same.

25. Dilution What volume of 15.8M HNO 3 is required to make 250 mL of a 6.0M solution? GIVEN: M 1 = 15.8M V 1 = ? M 2 = 6.0M V 2 = 250 mL WORK: M 1 V 1 = M 2 V 2 (15.8M) V 1 = (6.0M)(250mL) V 1 = 95 mL of 15.8M HNO 3

28. Preparing Solutions 500 mL of 1.54M NaCl 500 mL water 45.0 g NaCl mass 45.0 g of NaCl add water until total volume is 500 mL mass 45.0 g of NaCl add 0.500 kg of water 500 mL mark 500 mL volumetric flask  1.54m NaCl in 0.500 kg of water

29. Preparing Solutions 250 mL of 6.0M HNO 3 by dilution measure 95 mL of 15.8M HNO 3 95 mL of 15.8M HNO 3 water for safet y 250 mL mark combine with water until total volume is 250 mL Safety: “Do as you oughtta, add the acid to the watta!”

30. Percent solutions can be expressed by a) volume or b) mass Percent means parts per 100, so Percent by volume: = Volume of solute x 100% Volume of solution indicated %(v/v) Sample Problem 16.5, page 485

31. Percent solutions Another way to do mass percentage is as mass/mass: Percent by mass: = Mass of solute(g) x 100% Mass of solution (g) Indicated %(m/m)

32. property that depends on the concentration of solute particles, not their identity Colligative Property

33. Types Freezing Point Depression Freezing Point Depression (  t f ) f.p. of a solution is lower than f.p. of the pure solvent Boiling Point Elevation Boiling Point Elevation (  t b ) b.p. of a solution is higher than b.p. of the pure solvent Vapor pressure lowering Vapor pressure lowering

34. - Page 488 Glucose will only have one particle in solution for each one particle it starts with. NaCl will have two particles in solution for each one particle it starts with. CaCl 2 will have three particles in solution for each one particle it starts with. Colligative Properties Some particles in solution will IONIZE (or split), while others may not.

35. Freezing Point Depression

36. Solute particles weaken IMF in the solvent. Boiling Point Elevation

37. - Page 494 The addition of a solute would allow a LONGER temperature range, since freezing point is lowered and boiling point is elevated.

38. Applications salting icy roads making ice cream antifreeze cars (-64°C to 136°C)