The document discusses various concepts related to solutions and chemical equilibria including: 1) Types of solutions and units of concentration like molarity and ppm. 2) Factors that affect solubility, boiling point, and freezing point when a solute is added. 3) Equilibrium constants and how they relate concentrations of reactants and products. 4) Le Chatelier's principle which states that systems at equilibrium will respond to stresses like changes in concentration, pressure, or temperature to reduce the stress.

1. Solutions Mixtures: Homogeneous and Heterogeneous Uniform Non-uniform

2. Solutions Concentrated or Dilute Units of concentration: Ppm/ppb vs. Molarity

3. Concentration Parts per million (ppm) mass of solute ppm = mass of solution x 100%

4. Concentration Molarity = moles/Liter

5. Molarity Vinegar What is the molarity if 3.78 g of CH 3 CO 2 H are dissolved in 100 mL?

6. Molarity Vinegar What is the molarity if 3.78 g of CH 3 CO 2 H are dissolved in 100 mL? 1 mole 3.78 g x 60 g = 0.063 moles Molarity = 0.063 moles/0.1 L = 0.63 M

7. Effects of Solutes Adding a dissolved substance to a solvent:

8. Effects of Solutes Adding a dissolved substance to a solvent: Less solvent molecules evaporate at the regular boiling point: Higher boiling point

9. Boiling Point Elevation Adding salt to cooking pasta Makes the pasta cook faster

10. Effect of Solutes Added solute makes it harder for the solvent to freeze So a lower freezing point occurs

11. Ice Cream! Milkfat + +dissolved sugar + Air + flavor

12. Solubility Like dissolves Like Miscible Oil + Water = immiscible

13. Surfactants Surface – active Agent Polar/ non-polar go-between

14. Solubility & Temperature Solubility increases with temperature

15. Saturation When the maximum amount of solute is dissolved in a solution

16. Henry’s Law The solubility of a gas in a solution increases as the partial pressure of the gas on the surface of the solution increases.

17. Henry’s Law Carbonated Drinks: What happens when you open the bottle?

18. Molarity & Stoichiometry Recall Displacement Reactions: Cu + 2 AgNO 3 ---> 2 Ag + Cu(NO 3 ) 2 How much 0.5 M Silver Nitrate solution is needed to react with 0.317 g Cu metal?

19. Molarity & Stoichiometry Cu + 2 AgNO 3 ---> 2 Ag + Cu(NO 3 ) 2 0.317 g Cu x 1 mole/63.45 g = 0.05 moles Cu 2 moles AgNO 3 0.05 moles Cu x 1 mole Cu = 0.1 mole AgNO 3 0.1 moles AgNO 3 x 1 Liter/0.5 moles = 0.05 L = 50 mL

20. Chemical Equilibrium Balance point when the forward and reverse reaction rates are equal Photochromatic lenses

21. Reversible Reactions Forward Reaction 2 NO 2 -----> N 2 O 4 Reverse Reaction N 2 O 4 -----> 2 NO 2

22. Reversible Reactions Forward Reaction 2 NO 2 -----> N 2 O 4 Reverse Reaction N 2 O 4 -----> 2 NO 2 2 NO 2 N 2 O 4

23. Chemical Equilibrium Balance point where the rate of the forward reaction equals the rate of the reverse reaction Concentrations of products and reactants remain unchanged

24. Equilibrium Constant A + B C + D [C] [D] K eq = [A] [B] if K eq > 1 mostly products (C & D) if K eq < 1 mostly reactants (A & B) if K eq = 1 Equal amounts of reactants, products

25. Equilibrium Constants Balance the equation Leave out any solids or liquids (s), (l) Raise the substance’s concentration to the power equal to its coefficient

26. Equilibrium Constant COCl 2 (g) CO(g) + Cl 2 (g) K eq = ?

27. Equilibrium Constant COCl 2 (g) CO(g) + Cl 2 (g) [CO][Cl 2 ] K eq = [COCl 2 ] If [CO] = [Cl 2 ] = 0.0178 and [COCl 2 ] = 0.007, K eq = ???

28. Equilibrium Constant COCl 2 (g) CO(g) + Cl 2 (g) [CO][Cl 2 ] K eq = [COCl 2 ] If [CO] = [Cl 2 ] = 0.0178 and [COCl 2 ] = 0.007, K eq = 0.045

29. Equilibrium Constants N 2(g) + O 2(g) 2 NO (g) [NO] 2 K eq = [N 2 ][O 2 ]

30. Equilibrium Constants H 2 + I 2 2 HI [HI] 2 K eq = [H 2 ][I 2 ] At 25°C, [H 2 ] = [I 2 ] = 0.05 M, [HI] = 0.389M [HI] 2 (0.389)2 K eq = [H 2 ][I 2 ] = (0.05)(0.05) = 60.3

31. Equilibrium Constants H 2 + I 2 2 HI [HI] 2 K eq = [H 2 ][I 2 ] At 0°C, [H 2 ] = [I 2 ] = 0.0057 M, [HI] = 0.0127M [HI] 2 (0.0127) 2 K eq = [H 2 ][I 2 ] = (0.0057)(0.0057) = 4.96

32. Solubility Product K sp AgCl (s) Ag + (aq) + Cl – (aq) K sp = [Ag + ][Cl - ]

33. Tooth Enamel Hydroxyapatite Ca 5 (PO 4 ) 3 OH Fluorine treatment H 2 SiF 6 Ca 5 (PO 4 ) 3 F

34. Solubility Product How much Hg 2+ ion would be found in a pond where cinnabar was located? HgS Hg 2+ + S 2- K sp = 1 x 10 -53

35. Solubility Product How much Hg 2+ ion would be found in a pond where cinnabar was located? HgS Hg 2+ + S 2- K sp = 1 x 10 -53 = [Hg 2+ ][S 2- ] ([Hg 2+ ] = [S 2-] )

36. Solubility Product How much Hg 2+ ion would be found in a pond where cinnabar was located? HgS Hg 2+ + S 2- K sp = 1 x 10 -53 = [Hg 2+ ][S 2- ] ([Hg 2+ ] = [S 2-] ) [Hg 2+ ] = 3.16 x 10 -27

37. Solubility Product K sp

38. Equilibrium Stresses LeChatelier’s Principle: If a change occurs to a system at equilibrium, the system will react to reduce the stress Concentration Pressure Temperature

39. LeChatelier’s Principle Changes in Concentration (adding or removing reactant or product) CO + H 2 CH 3 OH To increase CH 3 OH: Add CO or H 2 OR remove CH 3 OH

40. LeChatelier’s Principle Changes in Pressure 2 NO 2(g) N 2 O 4(g)

41. LeChatelier’s Principle Changes in Pressure 2 NO 2(g) N 2 O 4(g) 2 moles of gas 1 mole of gas Increasing Pressure: Shifts equiibrium to N 2 O 4 side Decreasing Pressure: Shifts equilibrium to NO 2 side (Remember if volume decreases, pressure increases)

42. LeChatelier’s Principle Changes in Temperature Exothermic reactions Heat is a product Endothermic Reactions Heat is a reactant

43. LeChatelier’s Principle Changes in Temperature Exothermic reaction C 2 H4 + H 2 C 2 H 6 + heat Adding heat is like adding product so raising the temperature shifts the equilibrium toward C 2 H 4 and H 2

44. LeChatelier’s Principle Endothermic Reactions H 2 + F 2 + heat 2 HF Raising temperature = adding heat = adding reactant Equilibrium shifts to form more HF