1. AP Net Ionic Equations

2. AP equations are found in the free response section of the AP test
AP equations are found in the free response section of the AP test. You will have 3 equations following by a question about the reaction. The equations are of mixed types.

3. The sections is worth 15 points and is 10% of the free response grade
The sections is worth 15 points and is 10% of the free response grade. Free response is 50% of the total AP test grade.

4. All AP equations “work. ” In each case, a reaction will occur
All AP equations “work.” In each case, a reaction will occur. These equations need to be written in net ionic form. All spectator ions must be left out and all ions must be written in ionic form.

5. Answer 3 equations that must be balanced.
Each equation is followed by a question.
1 pt for reactants, 2 points for products, and 1 pt for each question.

6. Strong Acids are:
Exception: concentrated sulfuric acid-keep together because it really is 97% H2SO4 and 3% water in the jug.
Strong Bases are:

7. Weak acids and bases keep together

8. All molecular substances and nonsoluble compounds must be written together (not ionized!).

9. Know your solubility rules!!!
Ca(OH)2 and Sr(OH) 2 are moderately soluble and can be written together or as ions.
Ba(OH)2 is soluble and Mg(OH)2 is insoluble.
CaSO4 and SrSO4 are moderately soluble and can be written together or as ions.
Weak electrolytes, such as acetic acid, are not ionized.
Solids and pure liquids are written together, also.
A saturated solution is written in ionic form while a suspension is written together.

10. Double Replacement
Two compounds react to form two new compounds. No changes in oxidation numbers occur. All double replacement reactions must have a “driving force” that removes a pair of ions from solution.

11. Manganese(II) nitrate solution is mixed with a sodium hydroxide solution

12. Excess hydrochloric acid is added to an aqueous solution of potassium sulfite

13. Hydrogen sulfide gas is bubbled through a solution of lead(II) nitrate

14. A solution of ammonium sulfate is added to a potassium hydroxide solution

15. Solutions of tripotassium phosphate and zinc nitrate are mixed

16. Gaseous hydrofluoric acid reacts with solid silicon dioxide.

17. Single Replacement Rxns
Treat like redox reactions.
Reaction where one element displaces another in a compound. One element is oxidized and another is reduced.
A + BC  B + AC
+ charges replace + and
– charges replace -

18. Active metals replace less active metals or hydrogen from their compounds in aqueous solution.

19. Active nonmetals replace less active nonmetals from their compounds in aqueous solution. Each halogen will displace less electronegative (heavier) halogens from their binary salts.

20. Examples
A piece of aluminum metal is added to a solution of silver nitrate

21. Small chunks of solid sodium are added to water

22. Chlorine gas is bubbled into a solution of sodium bromide

23. Magnesium turnings are added to a solution of iron(III) chloride

24. Anhydrides Anhydride means “without water.”
Water is a reactant in each of these equations.

25. Memorize the Rules Look for: 1. Oxides + H2O
a. metallic oxide + H2O  base
b. nonmetallic oxide + H2O  acid

26. 2. Metal hydride + H2O metal hydroxide + H2

27. 3. Group 1 and 2 nitride + H2O
metal hydroxide + NH3

28. 4. Phosphorus halide + H2O 
H3PO4 or H3PO3 + H(halide) acid

29. Examples
Excess water is added to solid calcium hydride

30. Solid lithium hydride is added to water

31. Solid dinitrogen pentoxide is added to water

32. Solid potassium oxide is added to water

33. Phosphorus pentachloride solid is added to water

34. Methylamine gas is bubbled into distilled water

35. Oxidation-Reduction Reactions
Redox reactions involve the transfer of electrons. The oxidation numbers of at least two elements must change.
Single replacement, some combination and some decomposition reactions are redox reactions.

36. To predict the products of a redox reaction, look at the reagents given to see if there is both an oxidizing agent and a reducing agent.
When a problem mentions an acidic or basic solution, it is probably redox.

37. Common oxidizing agent
Product formed
MnO4- in acidic solution
Mn2+
MnO2 in acidic solution
MnO4- in neutral or basic solution
MnO2 (s)
Cr2O72- in acidic solution
Cr3+
HNO3, concentrated
NO2
HNO3, dilute NO
H2SO4, hot, concentrated
SO2

38. Common oxidizing agent
Product formed
Metal-ic ions
Metal-ous ions
Free halogens
Halide ions
Na2O2
NaOH
HClO4
Cl-
H2O2
H2O

39. Common reducing agent
Product formed
Halide ions
Free halogen
Free metals
Metal ions
Sulfite ions or SO2
Sulfate ions
Nitrite ions
Nitrate ions

40. Common reducing agent
Product formed
Free halogens, dilute basic solution
Hypohalite ions
Free halogens, conc. basic solution
Halate ions
Metal-ous ions
Metal-ic ions
H2O2 O2
C2O42-
CO2

41. Examples
A solution of tin(II) chloride is added to an acidified solution of potassium permanganate.

42. Hydrogen peroxide solution is added to a solution of iron(II) sulfate

43. Potassium permanganate solution is added to a solution of oxalic acid acidified with a few drops of sulfuric acid.

44. A piece of iron is added to a solution of iron(III) sulfate.

45. Solid sodium dichromate is added to an acidified solution of sodium iodide

46. Potassium permanganate is mixed with an alkaline solution of sodium sulfite

47. Copper (II) sulfide is oxidized by dilute nitric acid.

48. A solution of potassium iodide is added to an acidified solution of potassium dichromate.

49. Acid-Base Neutralization Rxns
Acids react with bases to produce water and salts.

50. Examples
Hydrogen sulfide gas is bubbled through a solution of potassium hydroxide

51. A solution of sodium hydroxide is added to a solution of sodium dihydrogen phosphate until the same number of moles of each compound has been added

52. Nitric acid is added to crystals of pure calcium oxide

53. Carbon dioxide is bubbled through a solution of sodium hydroxide

54. Decomposition Reactions
Reaction where a compound breaks down into two or more elements or compounds. Heat, electrolysis, or a catalyst is usually necessary.

55. Memorize the rules!
1. Metal Carbonate  Metal oxide + CO2
2. Metal Chlorate  Metal chloride + O2

56. 3. Hydrogen peroxide water + oxygen
4. Ammonium carbonate ammonia water + carbon dioxide
5. Sulfurous acid  Sulfur dioxide + water
6. Carbonic acid  carbon dioxide + water

57. Examples
A solution of hydrogen peroxide is heated

58. Magnesium carbonate is heated

59. Potassium chlorate is heated in the presence of manganese dioxide

60. Solid ammonium carbonate is heated

61. Addition Reactions
Two or more elements or compounds combine to form a single product.

62. Memorize the rules! Most of these should already look familiar.
1. 2 cmpds  form one compound
2. If excess use the higher oxidation number
If limited use the lower oxidation number

63. 3. Nonmetal oxide + water  acid
4. Metal oxide + water  base
5. Metal oxide + sulfur dioxide Metal sulfite
6. Metal oxide + carbon dioxide  metal carbonate

64. Examples
Magnesium oxide is added to a container of carbon dioxide gas

65. Solid calcium oxide is heated in the presence of sulfur trioxide gas

66. Calcium metal is heated strongly in nitrogen gas

67. The gases boron trifluoride and ammonia are mixed

68. Combustion Reactions
-Elements or compounds combine with oxygen.

69. Memorize these rules. Hydrocarbon + oxygen  carbon dioxide + water
2. ammonia + oxygen  NO + H2O
if excess O2  NO2 + H2O

70. 3. Nonmetal hydride + oxygen  nonmetal oxide+ water
4. Nonmetal sulfide+oxygen  nonmetal oxide + sulfur dioxide

71. Methane is burned in the presence of oxygen

72. Lithium metal is burned in air

73. Solid zinc sulfide is heated in an excess of oxygen

74. A piece of solid bismuth is heated strongly in oxygen

75. Complex Ion Reactions
Complex ions are made up of a ____________ and a _____________.
[Co(NH3)6]+3 is the complex ion
NH3 is the ligand, Co is the metal

76. Possible metals: Cu/Zn/Ag/Cd/Fe/Al
Possible ligands: NH3, OH-1, SCN-1
Magic number? Double charge to get magic number
Exceptions to the trick:
**[Al(OH)4] **[Fe(SCN)]2+

77. Example:
[Co(NH3)6] Cl3
NH3 is the ligand, [Co(NH3)6]+3 is the complex ion

78. Common complex ions on AP equations
**[Al(OH)4]- tetrahydroxoaluminate ion
formed from: (Al or Al(OH)3 or Al3+ + OH-)
[Ag(NH3)2]+ diamminesilver(I) ion
formed from (Ag+ + NH3)

79. [Zn(OH)4]2- tetrahydroxyzincate ion
formed from (Zn(OH)2 + OH-)
[Zn(NH3)4]2+ tetramminezinc ion
formed from (Zn NH3)
[Cu(NH3)4]2+ tetraminecopper(II) ion
formed from (Cu NH3)

80. [Cd(NH3)4]2+ tetraminecadmium(II) ion
formed from (Cd NH3)
**[Fe(SCN)]2+ thiocyanairon(III) ion
formed from (Fe SCN-)
[Ag(CN)2]- dicyanoargentate(I) ion
formed from (Ag+ and CN-)

81. Remember the following when writing complex ion reactions:
Acid to complex ion  break it up
2. Acid to NH3 complex  NH4+ + breakup complex ion
3. HCl + Ag complex  AgCl + Breakup complex ion

82. Examples
Concentrated (15M) ammonia is added in excess to a solution of copper (II) nitrate

83. Dilute hydrochloric acid is added to a solution of tetraminecopper (II) sulfate

84. A suspension of zinc hydroxide is treated with concentrated sodium hydroxide solution

85. Solid silver chloride is added to a concentrated solution of ammonia

86. Hydrochloric acid is added to a solution of dihydroxysilver bromide