2. LO 1.4: The student is able to connect the number of particles, moles, mass, and volume of substances to one another, both qualitatively and quantitatively. (Sec 4.3)
LO 1.17: The student is able to express the law of conservation of mass quantitatively and qualitatively using symbolic representations and particulate drawings. (Sec 4.5)
LO 1.18: The student is able to apply conservation of atoms to the rearrangement of atoms in various processes. (Sec 4.9)
LO 2.8: The student can draw and/or interpret representations of solutions that show the interactions between the solute and solvent. (Sec )
LO 2.9: The student is able to create or interpret representations that link the concept of molarity with particle views of solutions. (Sec )
LO 2.14: The student is able to apply Coulomb’s Law qualitatively (including using representations) to describe the interactions of ions, and the attractions between ions and solvents to explain the factors that contribute to the solubility of ionic compounds. (Sec 4.1)

3. LO 3.1: Students can translate among macroscopic observations of change, chemical equations, and particle views. (Sec )
LO 3.2: The student can translate an observed chemical change into a balanced chemical equation and justify the choice of equation type (molecular, ionic, or net ionic) in terms of utility for the given circumstances. (Sec )
LO 3.3: The student is able to use stoichiometric calculations to predict the results of performing a reaction in the laboratory and/or to analyze deviations from the expected results. (Sec 4.8)
LO 3.4: The student is able to relate quantities (measured mass of substances, volumes of solutions, or volumes and pressures of gases) to identify stoichiometric relationships for a reaction, including situations involving limiting reactants and situations in which the reaction has not gone to completion. (Sec 4.8)
LO 3.8: The student is able to identify redox reactions and justify the identification in terms of electron transfer. (Sec 4.9)

4. LO 3.9: The student is able to design and/or interpret the results of an experiment involving a redox titration. (Sec )
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions. (Sec )

5. AP Learning Objectives, Margin Notes and References
LO 2.8: The student can draw and/or interpret representations of solutions that show the interactions between the solute and solvent.
LO 2.9: The student is able to create or interpret representations that link the concept of molarity with particle views of solutions.
LO 2.14: The student is able to apply Coulomb’s Law qualitatively (including using representations) to describe the interactions of ions, and the attractions between ions and solvents to explain the factors that contribute to the solubility of ionic compounds.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

6. One of the most important substances on Earth.
Can dissolve many different substances.
A polar molecule because of its unequal charge distribution.
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7. Dissolution of a solid in a liquid
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8. AP Learning Objectives, Margin Notes and References
LO 2.8: The student can draw and/or interpret representations of solutions that show the interactions between the solute and solvent.
LO 2.9: The student is able to create or interpret representations that link the concept of molarity with particle views of solutions.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

9. Nature of Aqueous Solutions
Solute – substance being dissolved.
Solvent – liquid water.
Electrolyte – substance that when dissolved in water produces a solution that can conduct electricity.
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10. Electrolytes
Strong Electrolytes – conduct current very efficiently (bulb shines brightly). Completely ionized in water.
Weak Electrolytes – conduct only a small current (bulb glows dimly). A small degree of ionization in water.
Nonelectrolytes – no current flows (bulb remains unlit). Dissolves but does not produce any ions.
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11. Electrolyte behavior To play movie you must be in Slide Show Mode
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12. AP Learning Objectives, Margin Notes and References
LO 1.4: The student is able to connect the number of particles, moles, mass, and volume of substances to one another, both qualitatively and quantitatively.
LO 2.8: The student can draw and/or interpret representations of solutions that show the interactions between the solute and solvent.
LO 2.9: The student is able to create or interpret representations that link the concept of molarity with particle views of solutions.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

13. Chemical Reactions of Solutions
We must know:
The nature of the reaction.
The amounts of chemicals present in the solutions.
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14. Molarity
Molarity (M) = moles of solute per volume of solution in liters:
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15. EXERCISE!
A g sample of potassium phosphate is dissolved in enough water to make 1.50 L of solution. What is the molarity of the solution?
1.57 M
500.0 g is equivalent to mol K3PO4 (500.0 g / g/mol). The molarity is therefore 1.57 M (2.355 mol/1.50 L).
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16. Concentration of Ions For a 0.25 M CaCl2 solution: CaCl2 → Ca2+ + 2Cl–
Ca2+: 1 × 0.25 M = 0.25 M Ca2+
Cl–: 2 × 0.25 M = 0.50 M Cl–.
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17. Which of the following solutions contains the greatest number of ions?
CONCEPT CHECK!
Which of the following solutions contains the greatest number of ions?
400.0 mL of 0.10 M NaCl.
300.0 mL of 0.10 M CaCl2.
200.0 mL of 0.10 M FeCl3.
800.0 mL of 0.10 M sucrose.
a) contains mol of ions (0.400 L × 0.10 M × 2). b) contains mol of ions (0.300 L × 0.10 M × 3). c) contains mol of ions (0.200 L × 0.10 M × 4). d) does not contain any ions because sucrose does not break up into ions. Therefore, letter b) is correct.
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18. Let’s Think About It Where are we going?
To find the solution that contains the greatest number of moles of ions.
How do we get there?
Draw molecular level pictures showing each solution. Think about relative numbers of ions.
How many moles of each ion are in each solution?
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19. Notice
The solution with the greatest number of ions is not necessarily the one in which:
the volume of the solution is the largest.
the formula unit has the greatest number of ions.
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20. Dilution
The process of adding water to a concentrated or stock solution to achieve the molarity desired for a particular solution.
Dilution with water does not alter the numbers of moles of solute present.
Moles of solute before dilution = moles of solute after dilution
M1V1 = M2V2
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21. Add water to the solution.
CONCEPT CHECK!
A 0.50 M solution of sodium chloride in an open beaker sits on a lab bench. Which of the following would decrease the concentration of the salt solution?
Add water to the solution.
Pour some of the solution down the sink drain.
c) Add more sodium chloride to the solution.
d) Let the solution sit out in the open air for a couple of days.
e) At least two of the above would decrease the concentration of the salt solution.
For letter a), adding water to the solution will increase the total volume of solution and therefore decrease the concentration. For letter b), pouring some of the solution down the drain will not change the concentration of the salt solution remaining. For letter c), adding more sodium chloride to the solution will increase the number of moles of salt ions and therefore increase the concentration. For letter d), water will evaporate from the solution and decrease the total volume of solution and therefore increase the concentration. Therefore, since only letter a) would decrease the concentration, letter e) cannot be correct.
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22. EXERCISE!
What is the minimum volume of a 2.00 M NaOH solution needed to make mL of a M NaOH solution? 60.0 mL
The minimum volume needed is 60.0 mL. M1V1 = M2V2 (2.00 M)(V1) = (0.800 M)(150.0 mL)
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23. AP Learning Objectives, Margin Notes and References
LO 3.1: Students can translate among macroscopic observations of change, chemical equations, and particle views.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

24. Precipitation Reactions Acid–Base Reactions
Oxidation–Reduction Reactions
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25. AP Learning Objectives, Margin Notes and References
LO 1.17: The student is able to express the law of conservation of mass quantitatively and qualitatively using symbolic representations and particulate drawings.
LO 1.18: The student is able to apply conservation of atoms to the rearrangement of atoms in various processes.
LO 3.1: Students can translate among macroscopic observations of change, chemical equations, and particle views.
LO 3.2: The student can translate an observed chemical change into a balanced chemical equation and justify the choice of equation type (molecular, ionic, or net ionic) in terms of utility for the given circumstances.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

26. Precipitation Reaction
A double displacement reaction in which a solid forms and separates from the solution.
When ionic compounds dissolve in water, the resulting solution contains the separated ions.
Precipitate – the solid that forms.
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27. The Reaction of K2CrO4(aq) and Ba(NO3)2(aq)
Ba2+(aq) + CrO42–(aq) → BaCrO4(s)
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28. Precipitation of Silver Chloride
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29. Precipitates
Soluble – solid dissolves in solution; (aq) is used in reaction equation.
Insoluble – solid does not dissolve in solution; (s) is used in reaction equation.
Insoluble and slightly soluble are often used interchangeably.
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30. Simple Rules for Solubility
Most nitrate (NO3-) salts are soluble.
Most alkali metal (group 1A) salts and NH4+ are soluble.
Most Cl-, Br-, and I- salts are soluble (except Ag+, Pb2+, Hg22+).
Most sulfate salts are soluble (except BaSO4, PbSO4, Hg2SO4, CaSO4).
Most OH- are only slightly soluble (NaOH, KOH are soluble, Ba(OH)2, Ca(OH)2 are marginally soluble).
Most S2-, CO32-, CrO42-, PO43- salts are only slightly soluble, except for those containing the cations in Rule 2.
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31. CONCEPT CHECK!
Which of the following ions form compounds with Pb2+ that are generally soluble in water? a) S2– b) Cl– c) NO3– d) SO42– e) Na+
a), b), and d) all form precipitates with Pb2+. A compound cannot form between only Pb2+ and Na+.
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32. AP Learning Objectives, Margin Notes and References
LO 3.1: Students can translate among macroscopic observations of change, chemical equations, and particle views.
LO 3.2: The student can translate an observed chemical change into a balanced chemical equation and justify the choice of equation type (molecular, ionic, or net ionic) in terms of utility for the given circumstances.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

33. Formula Equation (Molecular Equation)
Gives the overall reaction stoichiometry but not necessarily the actual forms of the reactants and products in solution.
Reactants and products generally shown as compounds.
Use solubility rules to determine which compounds are aqueous and which compounds are solids.
AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq)
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34. Complete Ionic Equation
All substances that are strong electrolytes are represented as ions.
Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq)
AgCl(s) + Na+(aq) + NO3-(aq)
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35. Ag+(aq) + Cl-(aq) AgCl(s)
Net Ionic Equation
Includes only those solution components undergoing a change.
Show only components that actually react.
Ag+(aq) + Cl-(aq) AgCl(s)
Spectator ions are not included (ions that do not participate directly in the reaction).
Na+ and NO3- are spectator ions.
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36. CONCEPT CHECK!
Write the correct formula equation, complete ionic equation, and net ionic equation for the reaction between cobalt(II) chloride and sodium hydroxide.
Formula Equation:
CoCl2(aq) + 2NaOH(aq) Co(OH)2(s) + 2NaCl(aq)
Complete Ionic Equation:
Co2+(aq) + 2Cl-(aq) + 2Na+(aq) + 2OH-(aq)
Co(OH)2(s) + 2Na+(aq) + 2Cl-(aq)
Net Ionic Equation:
Co2+(aq) + 2Cl-(aq) Co(OH)2(s)
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37. AP Learning Objectives, Margin Notes and References
LO 3.1: Students can translate among macroscopic observations of change, chemical equations, and particle views.
LO 3.2: The student can translate an observed chemical change into a balanced chemical equation and justify the choice of equation type (molecular, ionic, or net ionic) in terms of utility for the given circumstances.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

38. Solving Stoichiometry Problems for Reactions in Solution
Identify the species present in the combined solution, and determine what reaction occurs.
Write the balanced net ionic equation for the reaction.
Calculate the moles of reactants.
Determine which reactant is limiting.
Calculate the moles of product(s), as required.
Convert to grams or other units, as required.
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39. What precipitate will form? lead(II) phosphate, Pb3(PO4)2
CONCEPT CHECK!
(Part I)
10.0 mL of a 0.30 M sodium phosphate solution reacts with 20.0 mL of a 0.20 M lead(II) nitrate solution (assume no volume change).
What precipitate will form?
lead(II) phosphate, Pb3(PO4)2
What mass of precipitate will form?
1.1 g Pb3(PO4)2
The balanced molecular equation is: 2Na3PO4(aq) + 3Pb(NO3)2(aq) → 6NaNO3(aq) + Pb3(PO4)2(s).
mol Na3PO4 present to start and mol Pb(NO3)2 present to start. Pb(NO3)2 is the limiting reactant, therefore mol of Pb3(PO4)2 is produced. Since the molar mass of Pb3(PO4)2 is g/mol, 1.1 g of Pb3(PO4)2 will form.
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40. Let’s Think About It Where are we going? How do we get there?
To find the mass of solid Pb3(PO4)2 formed.
How do we get there?
What are the ions present in the combined solution?
What is the balanced net ionic equation for the reaction?
What are the moles of reactants present in the solution?
Which reactant is limiting?
What moles of Pb3(PO4)2 will be formed?
What mass of Pb3(PO4)2 will be formed?
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41. CONCEPT CHECK!
(Part II)
10.0 mL of a 0.30 M sodium phosphate solution reacts with 20.0 mL of a 0.20 M lead(II) nitrate solution (assume no volume change).
What is the concentration of nitrate ions left in solution after the reaction is complete?
0.27 M
The concentration of nitrate ions left in solution after the reaction is complete is 0.27 M.
Nitrate ions are spectator ions and do not participate directly in the chemical reaction. Since there were mol of Pb(NO3)2 present to start, then mol of nitrate ions are present. The total volume in solution is 30.0 mL. Therefore the concentration of nitrate ions = mol / L = 0.27 M.
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42. Let’s Think About It Where are we going?
To find the concentration of nitrate ions left in solution after the reaction is complete.
How do we get there?
What are the moles of nitrate ions present in the combined solution?
What is the total volume of the combined solution?
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43. CONCEPT CHECK!
(Part III)
10.0 mL of a 0.30 M sodium phosphate solution reacts with 20.0 mL of a 0.20 M lead(II) nitrate solution (assume no volume change).
What is the concentration of phosphate ions left in solution after the reaction is complete?
0.011 M
The concentration of phosphate ions left in solution after the reaction is complete is M.
Phosphate ions directly participate in the chemical reaction to make the precipitate. There were mol of Na3PO4 present to start, therefore there was mol of phosphate ions present to start mol of phosphate ions were used up in the chemical reaction, therefore mol of phosphate ions is leftover ( – mol).
The total volume in solution is 30.0 mL. Therefore the concentration of phosphate ions = mol / L = M.
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44. Let’s Think About It Where are we going?
To find the concentration of phosphate ions left in solution after the reaction is complete.
How do we get there?
What are the moles of phosphate ions present in the solution at the start of the reaction?
How many moles of phosphate ions were used up in the reaction to make the solid Pb3(PO4)2?
How many moles of phosphate ions are left over after the reaction is complete?
What is the total volume of the combined solution?
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45. AP Learning Objectives, Margin Notes and References
LO 3.1: Students can translate among macroscopic observations of change, chemical equations, and particle views.
LO 3.2: The student can translate an observed chemical change into a balanced chemical equation and justify the choice of equation type (molecular, ionic, or net ionic) in terms of utility for the given circumstances.
LO 3.3: The student is able to use stoichiometric calculations to predict the results of performing a reaction in the laboratory and/or to analyze deviations from the expected results.
LO 3.4: The student is able to relate quantities (measured mass of substances, volumes of solutions, or volumes and pressures of gases) to identify stoichiometric relationships for a reaction, including situations involving limiting reactants and situations in which the reaction has not gone to completion.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)
LO 3.13 (see APEC #4, “Analysis of Vinegar”)

46. Acid–Base Reactions (Brønsted–Lowry)
Acid—proton donor
Base—proton acceptor
For a strong acid and base reaction:
H+(aq) + OH–(aq) H2O(l)
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47. Neutralization of a Strong Acid by a Strong Base
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48. Performing Calculations for Acid–Base Reactions
List the species present in the combined solution before any reaction occurs, and decide what reaction will occur.
Write the balanced net ionic equation for this reaction.
Calculate moles of reactants.
Determine the limiting reactant, where appropriate.
Calculate the moles of the required reactant or product.
Convert to grams or volume (of solution), as required.
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49. Acid–Base Titrations
Titration – delivery of a measured volume of a solution of known concentration (the titrant) into a solution containing the substance being analyzed (the analyte).
Equivalence point – enough titrant added to react exactly with the analyte.
Endpoint – the indicator changes color so you can tell the equivalence point has been reached.
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50. CONCEPT CHECK!
For the titration of sulfuric acid (H2SO4) with sodium hydroxide (NaOH), how many moles of sodium hydroxide would be required to react with 1.00 L of M sulfuric acid to reach the endpoint? 1.00 mol NaOH
The balanced equation is: H2SO4 + 2NaOH → 2H2O + Na2SO moles of sulfuric acid is present to start. Due to the 1:2 ratio in the equation, 1.00 mol of NaOH would be required to exactly react with the sulfuric acid.
1.00 mol of sodium hydroxide would be required.
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51. Let’s Think About It Where are we going?
To find the moles of NaOH required for the reaction.
How do we get there?
What are the ions present in the combined solution? What is the reaction?
What is the balanced net ionic equation for the reaction?
What are the moles of H+ present in the solution?
How much OH– is required to react with all of the H+ present?
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52. AP Learning Objectives, Margin Notes and References
LO 1.18: The student is able to apply conservation of atoms to the rearrangement of atoms in various processes.
LO 3.1: Students can translate among macroscopic observations of change, chemical equations, and particle views.
LO 3.2: The student can translate an observed chemical change into a balanced chemical equation and justify the choice of equation type (molecular, ionic, or net ionic) in terms of utility for the given circumstances.
LO 3.8: The student is able to identify redox reactions and justify the identification in terms of electron transfer.
LO 3.9: The student is able to design and/or interpret the results of an experiment involving a redox titration.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.9 (see APEC #8, “Analysis by Oxidation-Reduction Titration”)
LO 3.9 (see Appendix 7.1 “Simple Oxidation-Reduction Titrations”)
LO 3.10 (see APEC #9, “Actions, Reactions, and Interactions”)

53. Redox Reactions
Reactions in which one or more electrons are transferred.
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54. Reaction of Sodium and Chlorine
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55. Rules for Assigning Oxidation States
Oxidation state of an atom in an element = 0
Oxidation state of monatomic ion = charge of the ion
Oxygen = -2 in covalent compounds (except in peroxides where it = -1)
Hydrogen = +1 in covalent compounds
Fluorine = -1 in compounds
Sum of oxidation states = 0 in compounds
Sum of oxidation states = charge of the ion in ions
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56. EXERCISE!
Find the oxidation states for each of the elements in each of the following compounds:
K2Cr2O7
CO32-
MnO2
PCl5
SF4
K = +1; Cr = +6; O = –2
C = +4; O = –2
Mn = +4; O = –2
P = +5; Cl = –1
S = +4; F = –1
K2Cr2O7; K = +1; Cr = +6; O = -2
CO32-; C = +4; O = -2
MnO2; Mn = +4; O = -2
PCl5; P = +5; Cl = -1
SF4; S = +4; F = -1
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57. Redox Characteristics
Transfer of electrons
Transfer may occur to form ions
Oxidation – increase in oxidation state (loss of electrons); reducing agent
Reduction – decrease in oxidation state (gain of electrons); oxidizing agent
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58. Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g)
CONCEPT CHECK!
Which of the following are oxidation-reduction reactions? Identify the oxidizing agent and the reducing agent.
Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g)
Cr2O72-(aq) + 2OH-(aq) CrO42-(aq) + H2O(l)
2CuCl(aq) CuCl2(aq) + Cu(s)
Zn – reducing agent; HCl – oxidizing agent
c) CuCl acts as the reducing and oxidizing agent
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59. AP Learning Objectives, Margin Notes and References
LO 3.9: The student is able to design and/or interpret the results of an experiment involving a redox titration.
LO 3.10: The student is able to evaluate the classification of a process as a physical change, chemical change, or ambiguous change based on both macroscopic observations and the distinction between rearrangement of covalent interactions and noncovalent interactions.
Additional AP References
LO 3.9 (see APEC #8, “Analysis by Oxidation-Reduction Titration”)
LO 3.9 (see Appendix 7.1 “Simple Oxidation-Reduction Titrations”)

60. Balancing Oxidation–Reduction Reactions by Oxidation States
Write the unbalanced equation.
Determine the oxidation states of all atoms in the reactants and products.
Show electrons gained and lost using “tie lines.”
Use coefficients to equalize the electrons gained and lost.
Balance the rest of the equation by inspection.
Add appropriate states.
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61. Balance the reaction between solid zinc and aqueous hydrochloric acid to produce aqueous zinc(II) chloride and hydrogen gas.
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62. 1. What is the unbalanced equation?
Zn(s) + HCl(aq) Zn2+(aq) + Cl–(aq) + H2(g)
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63. 2. What are the oxidation states for each atom?
Zn(s) + HCl(aq) Zn2+(aq) + Cl–(aq) + H2(g)
– –
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64. 3. How are electrons gained and lost?
1 e– gained (each atom)
Zn(s) + HCl(aq) Zn2+(aq) + Cl–(aq) + H2(g)
– –
2 e– lost
The oxidation state of chlorine remains unchanged.
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65. 4. What coefficients are needed to equalize the electrons gained and lost?
1 e– gained (each atom) × 2
Zn(s) + HCl(aq) Zn2+(aq) + Cl–(aq) + H2(g)
– –
2 e– lost
Zn(s) + 2HCl(aq) Zn2+(aq) + Cl–(aq) + H2(g)
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66. 5. What coefficients are needed to balance the remaining elements?
Zn(s) + 2HCl(aq) Zn2+(aq) + 2Cl–(aq) + H2(g)
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