1. SOLUTIONS A homogeneous mixture in which the components are uniformly intermingled

2. Properties of Water Triatomic molecule Contains covalent bonds (partial charges) – Where do the charges come from? Polar molecule

3. Hydrogen Bonds Intermolecular attractions between water molecules Affects surface tension and vapor pressure

4. Surface Tension Inward force that minimizes the surface area of a liquid Water molecules at the surface can not hydrogen bond with air therefore turn inward to form a skin

5. Surfactant Interferes with hydrogen bonding therefore reduces surface tension – Examples: Soaps and detergents – Cause water molecules to collapse

6. Vapor Pressure Vapor pressure is the pressure of the gas acting above the liquid in a sealed container Water has a low vapor pressure due to hydrogen bonds – Holds water molecules together – Evaporation is slow

7. Solid state of water Density decreases as water changes to a solid Honeycomb (hydrogen bonds hold H 2 O molecules in place)

8. Terms Solvent – The substance present in the largest amount in a solution. The substance that does the dissolving. Solute – The other substance or substances in a solution. The substance that is dissolved.

9. Solvation Positive and negative ions of an ionic solid become surrounded by solvent molecules (ionic solid dissolves)

10. Solvation Polar solvents dissolve polar molecules and ionic compounds – Example: Water and table salt Nonpolar solvents dissolve nonpolar solutes Example: Gasoline dissolves plastic

11. ELECTROLYTES Substances that break up in water to produce ions. NaCl (aq)  Na + (aq) + Cl - (aq) BaCl 2 (aq)  Ba +2 (aq) + 2Cl - (aq) AlCl 3 (aq)  Al +3 (aq) + 3Cl - (aq) These ions can conduct electric current Examples: Acids, Bases and Salts (ionic compounds)

12. Heterogeneous Mixtures Suspensions- large particle size (>1000nm); particles will settle out – Example: clay and water Colloids – smaller particle size than suspensions but larger than solutions (1nm to 1000nm) Solutions (homogenous mixture)- small particle size

13. Example:

14. Emulsion Colloidal dispersion of a liquid in a liquid Example: – Emulsifying agent – egg yolk

15. Comparison

16. SOLUBILITY Is the amount of a substance that dissolves in 100 g of water at a given temperature to produce a saturated solution “Like dissolves Like” – Polar molecules dissolve polar molecules – Nonpolar molecules dissolve nonpolar molecules

17. SOLUBILITY RULES All common salts of Group I elements and ammonium are soluble All common acetates and nitrates are soluble All binary compounds of Group 7 (other than F) with metals are soluble except those of silver, mercury I and lead All sulfates are soluble except those of barium, strontium, calcium, silver, mercury I and lead Except for those in Rule 1, carbonates, hydroxides, oxides, sulfides and phosphates are insoluble

18. Terms Saturated – When a solution contains the maximum amount of solute Unsaturated – When a solvent can dissolve more solute Supersaturated – When the solution contains more solute than a saturated solution will hold at that temperature Concentrated – When a relatively large amount of solute is dissolved Dilute – When a relatively small amount of solute is dissolved

19. Factors Affecting the Rate of Dissolution Surface Area Stirring Temperature

20. vs Solubility

21. MOLARITY Molarity-the number of moles of solute per liters of solution M = molarity = moles of solute liter of solution

22. Molarity Calculate the molarity of a solution prepared by dissolving 11.5 g of NaOH in enough water to make a 1.50 L solution.

23. Molarity Calculate the molarity of a solution prepared by dissolving 1.56 g of HCl into enough water to make 26.8 ml of solution.

24. Molarity What is the concentration of each ion in a 0.50 M solution of Co(NO 3 ) 2 ? What is the concentration of each ion in a 0.25 M solution of aluminum sulfate?

25. Molarity How many moles of Ag + ions are present in 25.0 ml of a 0.75 M AgNO 3 solution? Calculate the number of moles of Cl - ions in 1.75 L of 1.0 x 10 -3 M AlCl 3

26. Molarity To analyze the alcohol content of a certain wine, a chemist needs 1.00 L of an aqueous 0.200 M K 2 Cr 2 O 7 (molar mass is 294.2g/mol) How much K 2 Cr 2 O 7 must be weighed out to make this solution?

27. Making DILUTIONS M 1 x V 1 = M 2 x V 2 What volume of 16 M sulfuric acid must be used to prepare 1.5 L of a 0.10 M H 2 SO 4 What volume of 12 M HCl must be used to prepare 0.75 L of a 0.25 M HCl?

28. DILUTIONS When barium nitrate and potassium chromate react in aqueous solution, the yellow solid barium chromate is formed. Calculate the mass of barium chromate that forms when 3.50 x 10 -3 mole of solid barium nitrate is dissolved in 265 ml of 0.0100 M potassium chromate solution.

29. MASS PERCENT A unit of concentration equal to the mass of solute per mass of solution partx 100 whole

30. Mass Percent A solution is prepared by mixing 1.00 g of ethanol with 100.0 g of water. Calculate the mass percent of ethanol in this solution. A 135 g sample of seawater is evaporated to dryness, leaving 4.73 g of salt. Calculate the mass percent of salt in the saltwater.

31. MOLALITY A unit of concentration equal to the number of moles of solute per kilogram of solvent m = moles of solute kg solvent

32. MOLALITY 98.0 g RbBr in 824 g water 85.2 g SnBr 2 in 1.40 x 10 2 g water

33. Freezing Point Depression/ Boiling Point Elevation of Solutions Colligative property – a solution property that depends on the number of solute particles present – Particles can be ions, molecules or atoms – Freezing Point Depression The more particles in a solution, the lower the freezing point – Boiling Point Elevation The more particles in a solution, the higher the boiling point – Vapor Pressure Lowering The more particles in a solution, the lower the vapor pressure

34. When dissolved in water, the following substances will increase the boiling point of water. NaCl MgCl 2 AlCl 3 C 6 H 12 O 6 Al 2 (SO 4 ) 3 NaOH C 2 H 5 OH List the substances in order that will increase the boiling point from the least to the most: 1. Least: C 6 H 12 O 6 or C 2 H 5 OH (1 particle -- do not dissociate) 2. Next : NaCl or NaOH (2 particles) 3. Next: MgCl 2 (3 particles) 4. Next: AlCl 3 (4 particles) 5. Most: Al 2 (SO 4 ) 3 (5 particles) Freezing Point Depression/ Boiling Point Elevation of Solutions

35. Calculating Boiling Points K bp = boiling point constant – Water 0.512 O C/m – 1 mole of a solute particle will raise the bp of 1 kg of water by 0.512 O C 1m solution of sugar water 1(0.512 O C) 100.512 O C 1m solution of NaCl water 2(0.512 O C) 101.024 O C 1m solution of CaCl 2 water 3(0.512 O C) 101.536 O C

36. Calculating Freezing Points K fp = freezing point constant – Water 1.86 O C/m – 1 mole of a solute particle will lower the fp of 1 kg of water by 1.86 O C 1m solution of sugar water 1(1.86 O C) -1.86 O C 1m solution of NaCl water 2(1.86 O C) -3.72 O C 1m solution of CaCl 2 water 3(1.86 O C) -5.58 O C

37. Boiling Point Elevation & Freezing Point Depression ΔT fp = m K fp ΔT bp = m K bp K fp = 1.86 o C/mK bp = 0.512 o C/m If 26.4 grams of nickel II bromide are dissolved in 224 grams of water, what will be the new boiling point and freezing point of the resulting solution?

38. Boiling Point Elevation & Freezing Point Depression If 25.0 grams of calcium chloride are dissolved in 500 grams of water, what will be the new boiling point and freezing point of the resulting solution?

39. Molecular Mass Determination If 99.0 g of a nonionizing solute dissolved in 669 grams of water and the freezing point of the resulting solution is -0.960 o C, what is the molecular mass of the solute? ΔT fp = m K fp m = ΔT fp K fp

40. Molecular Mass Determination If 64.3 g of a nonionizing solute dissolved in 390. grams of water and the boiling point of the resulting solution is 100.680 o C, what is the molecular mass of the solute? ΔT bp = m K bp m = ΔT bp K bp