2. Ch4.1 – Types of Chemical Reactions and Solutions

3. This is the process of hydration.
Dissociation equation: NaCl(s) Na+(aq) + Cl–(ag)
H2O

4. Solubility varies greatly.
For ions - depends on who has the greater attraction.
For molecules – depends on polarity
Solvent – the substance doing the dissolving (water)
Solute – the substance that gets dissolved (salt)

5. Electrolytes
Strong electrolytes
- conduct current very efficiently
- soluble salts, acids, bases

6. - conduct current very efficiently - soluble salts, acids, bases
Electrolytes
Strong electrolytes
- conduct current very efficiently
- soluble salts, acids, bases
Arrhenius Theory of Acids
- produces H+ ions (protons) in water
HCl H2O H+(aq) + Cl–(aq)
- strong acid – vitrually every H ionizes
H2SO4 H2O H+(aq) + HSO4–(aq)

7. Weak electrolytes – only a small degree of ionization
Weak Acid Weak Base
HC2H3O2 H2O H+(aq) + C2H3O2–(aq) NH3 H2O NH4+(aq) + OH–(aq)
Only about 1 in 100 H’s ionize. The rest stay in their molecules.
Nonelectrolytes – dissolve in water, but don’t produce ions.
- like sugar (nonpolar substances)

8. Molarity
Units: Molar or M
Ex1) Calc the molarity of a solution prepared by dissolving 11.5g NaOH
in enough water to make 1.50L soln.

9. Concentration of Ions
Ex2) Give the concentration of ions in a 0.50M Co(NO3)2 soln.

10. Ex3) Calculate the number of moles of Cl– ions in
1.75L of 1.0x10-3M ZnCl2 soln.
Ch4 HW#1 p (d-g),13,15(a,b),17(a,b)

11. Ch4 HW#1 p180+ 11(d-g),13,15(a,b),17(a,b)
11. Show how each of the following strong electrolytes “ breaks up” into its component ions dissolving in water.
d. (NH4)2SO4
e. HI
f. FeSO4
g. KMnO4
h. HClO4
13. Calcium chloride is a strong electrolyte and is used to “salt” streets in the winter to melt ice and snow. Write a reaction to show how this substance breaks apart when it dissolves in water.

12. e. HI H2O H+ + I- f. FeSO4 H2O Fe+ + SO4- g. KMnO4 H2O K+ + MnO4-
Ch4 HW#1 p (d-g),13,15(a,b),17(a,b)
11. Show how each of the following strong electrolytes “ breaks up” into its component ions dissolving in water.
d. (NH4)2SO4 H2O 2NH4+ + SO4-2
e. HI H2O H+ + I-
f. FeSO4 H2O Fe+ + SO4-
g. KMnO4 H2O K+ + MnO4-
h. HClO4 H2O H+ + ClO4-
13. Calcium chloride is a strong electrolyte and is used to “salt” streets in the winter to melt ice and snow. Write a reaction to show how this substance breaks apart when it dissolves in water.

13. e. HI H2O H+ + I- f. FeSO4 H2O Fe+ + SO4- g. KMnO4 H2O K+ + MnO4-
Ch4 HW#1 p (d-g),13,15(a,b),17(a,b)
11. Show how each of the following strong electrolytes “ breaks up” into its component ions dissolving in water.
d. (NH4)2SO4 H2O 2NH4+ + SO4-2
e. HI H2O H+ + I-
f. FeSO4 H2O Fe+ + SO4-
g. KMnO4 H2O K+ + MnO4-
h. HClO4 H2O H+ + ClO4-
13. Calcium chloride is a strong electrolyte and is used to “salt” streets in the winter to melt ice and snow. Write a reaction to show how this substance breaks apart when it dissolves in water.
CaCl2 H2O Ca2+ + 2Cl-

14. 15.Calculate the molarity of each of these solutions.
a. A 5.623g sample of NaHCO3 is dissolved in enough water
to make 250 ml of solution.
b. A 184.6mg sample of K2Cr2O7 is dissolved in enough water
to make 500 ml of solution.

15. 15.Calculate the molarity of each of these solutions.
a. A 5.623g sample of NaHCO3 is dissolved in enough water
to make 250 ml of solution.
b. A 184.6mg sample of K2Cr2O7 is dissolved in enough water
to make 500 ml of solution.

16. 15.Calculate the molarity of each of these solutions.
a. A 5.623g sample of NaHCO3 is dissolved in enough water
to make 250 ml of solution.
b. A 184.6mg sample of K2Cr2O7 is dissolved in enough water
to make 500 ml of solution.

17. 17. Calculate the concentration of all ions present in each of the following solutions of strong electrolyte
a. 0.15M CaCl2
b. 0.26M Al(NO3)3

18. 17. Calculate the concentration of all ions present in each of the following solutions of strong electrolyte
a. 0.15M CaCl2
0.15M Ca+ ions
0.30M Cl- ions
b. 0.26M Al(NO3)3

19. 0.15M Ca+ ions 0.30M Cl- ions 0.78M NO3- ions
17. Calculate the concentration of all ions present in each of the following solutions of strong electrolyte
a. 0.15M CaCl2
0.15M Ca+ ions
0.30M Cl- ions
b. 0.26M Al(NO3)3
0.26M Al+3 ions
0.78M NO3- ions

20. Ch4.2 More Concentration Calculations
Ex1) Blood serum is 0.14M NaCl. What volume of blood contains
1.0mg NaCl?

21. Ex2) How would I prepare 500 mls of a 0.100M ______ solution,
given solid solute?

22. Dilutions
Ex3) How would I prepare 500 mls of a 0.100M H2SO4 solution,
given concentrated stock solution of 18M?
Ch4 HW#2 p181 21,23(a,b),25

23. Ch4 HW#2 p181 21,23(a,b),25
21. What volume of a M solution of NaHCO3 contains
0.350 g of NaHCO3?

24. Ch4 HW#2 p181 21,23(a,b),25
21. What volume of a M solution of NaHCO3 contains
0.350 g of NaHCO3?

25. 23. Describe how you would prepare 2.00 L of each of the following
solutions.
a M NaOH from solid NaOH
b M NaOH from 1.00M NaOH stock solution

26. 23. Describe how you would prepare 2.00 L of each of the following
solutions.
a M NaOH from solid NaOH
b M NaOH from 1.00M NaOH stock solution

27. 23. Describe how you would prepare 2.00 L of each of the following
solutions.
a M NaOH from solid NaOH
b M NaOH from 1.00M NaOH stock solution
b M1.V1 = M2.V2

28. 25. A solution is prepared by dissolving 10.8 g ammonium sulfate
in enough water to make mL of stock solution.
A 10.0 mL sample of this stock solution is added to 50.0 mL of water. Calculate the concentration of ammonium ions and sulfate ions in the final solution.

29. 25. A solution is prepared by dissolving 10.8 g ammonium sulfate
in enough water to make mL of stock solution.
A 10.0 mL sample of this stock solution is added to 50.0 mL of water. Calculate the concentration of ammonium ions and sulfate ions in the final solution.

30. Ch4.3 Types of Solution Reactions
1. Precipitation Reactions
2. Acid-base Reactions
3. Oxidation-Reduction Reactions (Redox)

31. 1. Precipitation Reactions
solns mixed and an insoluble substance forms, and separates,
called a precipitate.
AgNO3(aq) and NaCl(ag) 

32. 1. Precipitation Reactions
solns mixed and an insoluble substance forms, and separates,
called a precipitate.
K2CrO4(aq) + Ba(NO3)2(aq) 

33. Simple solubility rules for salts in water:
1. Most nitrates NO3-1 are soluble.
2. Most salts of alkali metals (Li+, Na+, K+, Cs+, Rb+ )
are soluble. Same for ammonium, NH4+ .
3. Most chloride, bromide, and iodide salts are soluble,
but not when with Ag+, Pb2+, Hg22+.
4. Most sulfates are soluble,
except BaSO4, PbSO4, Hg2SO4, CaSO4.
5. Most hydroxides are only slightly soluble,
except NaOH and KOH very soluble.
Ba(OH)2, Ca(OH)2, Sr(OH)2 only slightly soluble.
6. Most sulfides (S2–), carbonates (CO32–),
phosphates (PO43–), and chromtes (CrO42–)
are only slightly soluble.

34. b) Na2SO4(aq) and Pb(NO3)2(aq) c) KOH(aq) and Fe(NO3)3(aq)
Ex1) Use rules to predict what will happen if following solutions
are mixed:
a) KNO3(aq) and BaCl2(aq)
b) Na2SO4(aq) and Pb(NO3)2(aq)
c) KOH(aq) and Fe(NO3)3(aq)

35. 3 types of equations are used to describe reactions in solution:
1. molecular eqn – great for doing stoichiometry.
2. complete ionic eqn – all ions listed,
great for seeing strong electrolytes.
3. net ionic eqn – only those soln components
that undergo change. Spectators not included.
Ex2) Aqueous potassium hydroxide is mixed with aqueous iron(III) nitrate
to form a ppt of iron(III) hydroxide and aqueous potassium nitrate.
Write all 3 eqns.
Ch4 HW#3 p ,31,33,35(a,b)

36. d. NaOH(aq) + Fe(NO3)3(aq)
Ch4 HW#3 p ,31,33,35(a,b)
29. When the following solutions are mixed together,
what precipitation (if any) will form?
a. BaCl2(aq) + Na2SO4(aq)
b. Pb(NO3)2(aq) + KCl(aq)
c. AgNO3(aq) + Na3PO4(aq)
d. NaOH(aq) + Fe(NO3)3(aq)
31. For the reactions in Exercise 29, write the balanced molecular equation, complete ionic equation, and net ionic equation.
If no precipitate forms, write “No reaction.”

37. b. Pb(NO3)2(aq) + KCl(aq) PbCl2(c) c. AgNO3(aq) + Na3PO4(aq) Ag3PO4(s)
Ch4 HW#3 p ,31,33,35(a,b)
29. When the following solutions are mixed together,
what precipitation (if any) will form?
a. BaCl2(aq) + Na2SO4(aq) BaSO4(s)
b. Pb(NO3)2(aq) + KCl(aq) PbCl2(c)
c. AgNO3(aq) + Na3PO4(aq) Ag3PO4(s)
d. NaOH(aq) + Fe(NO3)3(aq) Fe(OH)3(s)
31. For the reactions in Exercise 29, write the balanced molecular equation, complete ionic equation, and net ionic equation.
If no precipitate forms, write “No reaction.”

38. NIE: a. BaCl2(aq) + Na2SO4(aq) BaSO4(s)
Ch4 HW#3 p ,31,33,35(a,b)
29. When the following solutions are mixed together,
what precipitation (if any) will form?
NIE: a. BaCl2(aq) + Na2SO4(aq) BaSO4(s)
NIE: b. Pb(NO3)2(aq) + KCl(aq) PbCl2(c)
NIE: c. AgNO3(aq) + Na3PO4(aq) Ag3PO4(s)
NIE: d. NaOH(aq) + Fe(NO3)3(aq) Fe(OH)3(s)
31. For the reactions in Exercise 29, write the balanced molecular equation, complete ionic equation, and net ionic equation.
If no precipitate forms, write “No reaction.”
BME:
a. BaCl2(aq) + Na2SO4(aq) Cl-(aq)+2Na+(aq)+ BaSO4(s)
b. Pb(NO3)2(aq) + 2KCl(aq) NO3-(aq)+2K+(aq)+ PbCl2(c)
c. 3AgNO3(aq)+Na3PO4(aq) NO3-(aq)+3Na+(aq)+Ag3PO4(s)
d. 3NaOH(aq)+Fe(NO3)3(aq) NO3-(aq)+3Na+(aq)+ Fe(OH)3(s)

39. a. AgNO3(aq) + KI(aq) b. CuSO4(aq) + Na2S(aq) c. CoCl2(aq) + NaOH(aq)
33. Write net ionic equations for each of the following.
a. AgNO3(aq) + KI(aq)
b. CuSO4(aq) + Na2S(aq)
c. CoCl2(aq) + NaOH(aq)
d. NiCI2(aq) + KNO3(aq)

40. Ag+(aq) + I-(aq) AgI(s) b. CuSO4(aq) + Na2S(aq)
33. Write net ionic equations for each of the following.
a. AgNO3(aq) + KI(aq)
Ag+(aq) + I-(aq) AgI(s)
b. CuSO4(aq) + Na2S(aq)
Cu2+(aq) + S2-(aq) CuS(s) (only slightly)
c. CoCl2(aq) + NaOH(aq)
Co2+(aq) + 2OH-(aq) Co(OH)2(aq) (only slightly)
d. NiCI2(aq) + KNO3(aq) No ppt

41. (NH4)2(SO4)(aq) + Ba(NO3)2(aq) 
35. Write net ionic equations for the reaction, if any, that occurs when aqueous solutions of the following are mixed.
a. Ammonium sulfate and barium nitrate
(NH4)2(SO4)(aq) + Ba(NO3)2(aq) 
b. Lead(II) nitrate and sodium chloride
Pb(NO3)2(aq) + NaCl(aq) 

42. SO42-(aq) + Ba2+(aq)  BaSO4(s)
35. Write net ionic equations for the reaction, if any, that occurs when aqueous solutions of the following are mixed.
a. Ammonium sulfate and barium nitrate
SO42-(aq) + Ba2+(aq)  BaSO4(s)
b. Lead(II) nitrate and sodium chloride
Pb+2(aq) Cl-(aq)  PbCl2(s)

43. Ch4.4 Mass of Precipitate
Ex1) Calculate the mass of solid NaCl that must be added
to 1.50L of a 0.100M AgNO3 solution to precipitate all the Ag+ ions.

44. Ex2) What mass of PbSO4 precipitates when
2.00L of 0.025M aqueous Na2SO4
and 1.25L of M aqueous Pb(NO3)2 are mixed?
Ch4 HW#4 p182 39,41,43

45. Ch4 HW#4 p182 39,41,43
39. What mass of NaCl is required to precipitate all the silver ions
from 50.0 mL of a M solution of AgNO3?
NaCl + AgNO3 
?g M
50.0ml

46. Ch4 HW#4 p182 39,41,43
39. What mass of NaCl is required to precipitate all the silver ions
from 50.0 mL of a M solution of AgNO3?
NaCl + AgNO3 
?g M
50.0ml
Cl Ag+  AgCl(s)

47. 41. What mass of solid aluminum hydroxide is produced when 50.0 mL
of M Al(NO3)3 is added to mL of 0.100M KOH?
Al(NO3) KOH 
0.200M M
50.0ml ml

48. 41. What mass of solid aluminum hydroxide is produced when 50.0 mL
of M Al(NO3)3 is added to mL of 0.100M KOH?
Al(NO3) KOH  K+(aq) + NO3-(aq) + Al(OH)3(s)
0.200M M ?g
50.0ml ml
Al is L.R.
x 3 = 0.06 mol

49. 0.200M 0.100M ?g 41. Al(NO3)3 + 3KOH  K+(aq) + NO3-(aq) + Al(OH)3(s)
50.0ml ml
Al is L.R.
x 3 = 0.06 mol

50. 43. A mL aliquot of M aqueous potassium hydroxide is mixed with mL of M aqueous magnesium nitrate.
a. Write a balanced chemical equation for any reaction that occurs.
b. What precipitate forms?
c. What mass of precipitate is produced?
d. Calculate the concentration of each ion remaining in solution
after precipitation is complete.

51. 2KOH + Mg(NO3)2  2K+ + 2NO3- + Mg2+ + 2OH-
43. A 100.0mL aliquot of M aqueous potassium hydroxide is mixed
with mL of M aqueous magnesium nitrate.
a. Write a balanced chemical equation for any reaction that occurs.
b. What precipitate forms?
c. What mass of precipitate is produced?
d. Calculate the concentration of each ion remaining in solution after precipitation is complete.
2KOH + Mg(NO3)2  2K+ + 2NO Mg OH-
2KOH + Mg(NO3)2  Mg(OH)2(s)
0.200M M
100ml ml LR

52. 2KOH + Mg(NO3)2  2K+ + 2NO3- + Mg(OH)2(s)
43. A 100.0mL aliquot of M aqueous potassium hydroxide is mixed
with mL of M aqueous magnesium nitrate.
d. Calculate the concentration of each ion remaining in solution after precipitation is complete.
2KOH + Mg(NO3)2  2K+ + 2NO3- + Mg(OH)2(s)
start:
end:

53. Ch4.4B – Ion Concentration
Ex1) A 100.0mL aliquot of M aqueous barium chloride is mixed
with mL of M aqueous sodium sulfate.
Barium sulfate precipitates out.
a. Write a balanced chemical equation for any reaction that occurs.
b. What mass of precipitate is produced?
c. Calculate the concentration of each ion remaining in solution after precipitation is complete.

54. BaCl2 + Na3SO4  3Na+ + 2Cl- + BaSO4(s)
c. Calculate the concentration of each ion remaining in solution
after precipitation is complete.
BaCl2 + Na3SO4  3Na+ + 2Cl BaSO4(s)
Ch4 HW#5 p182 44

55. Ch4 HW#5 p182 44
44. How many grams of silver chloride can be prepared by the reaction of 100.0mL of 0.20M silver nitrate with 100.0mL of 0.15M calcium chloride?
Calculate the concentration of each ion remaining in solution after precipitation is complete.
AgNO CaCl2  Ca NO AgCl(s)

56. AgNO3(aq) + CaCl2(aq)  AgCl(s) + Ca+2(aq) + NO3-(aq)
44. How many grams of silver chloride can be prepared by the reaction of 100.0ml of 0.20M silver nitrate with 100.0ml of 0.15M calcium chloride.
How much leftover of each ion?
Unbalanced:
AgNO3(aq) + CaCl2(aq)  AgCl(s) + Ca+2(aq) + NO3-(aq)
0.20M 0.15M ?g
0.1000L L
ions: Ag NO Ca Cl-
start:
end:

57. 2AgNO3(aq) + CaCl2(aq)  2AgCl(s) + Ca+2(aq) + 2NO3-(aq)
44. How many grams of silver chloride can be prepared by the reaction of 100.0ml of 0.20M silver nitrate with 100.0ml of 0.15M calcium chloride.
How much leftover of each ion?
Balanced Molecular Equation:
2AgNO3(aq) + CaCl2(aq)  2AgCl(s) + Ca+2(aq) + 2NO3-(aq)
0.20M M ?g
0.1000L L
ions: Ag NO Ca Cl-
start:
end:

58. 2AgNO3(aq) + CaCl2(aq)  2AgCl(s) + Ca+2(aq) + 2NO3-(aq)
44. How many grams of silver chloride can be prepared by the reaction of 100.0ml of 0.20M silver nitrate with 100.0ml of 0.15M calcium chloride.
How much leftover of each ion?
Balanced Molecular Equation:
2AgNO3(aq) + CaCl2(aq)  2AgCl(s) + Ca+2(aq) + 2NO3-(aq)
0.20M M ?g
0.1000L L
ions: Ag NO Ca Cl-
start:
end:

59. 2AgNO3(aq) + CaCl2(aq)  2AgCl(s) + Ca+2(aq) + 2NO3-(aq)
44. How many grams of silver chloride can be prepared by the reaction of 100.0ml of 0.20M silver nitrate with 100.0ml of 0.15M calcium chloride.
How much leftover of each ion?
Balanced Molecular Equation:
2AgNO3(aq) + CaCl2(aq)  2AgCl(s) + Ca+2(aq) + 2NO3-(aq)
0.20M M ?g
0.1000L L
ions: Ag NO Ca Cl-
start:
end:
The AgNO3 limits the reaction to produce 2.87g AgCl
But what about the ions leftover? Might consider solving this differently…

60. 2Ag+(aq)+ NO3–(aq)+Ca2++2Cl–(aq)2AgCl(s)+Ca+2(aq)+2NO3-(aq)
44. How many grams of silver chloride can be prepared by the reaction of 100.0ml of 0.20M silver nitrate with 100.0ml of 0.15M calcium chloride.
How much leftover of each ion?
Complete Ionic Equation: Look at the CIE, not the molecular equation:
2Ag+(aq)+ NO3–(aq)+Ca2++2Cl–(aq)2AgCl(s)+Ca+2(aq)+2NO3-(aq)
0.20M M M M g
0.1000L L L L
ions: Ag NO Ca Cl-
start: mol 0.02mol mol mol
end:

61. 2Ag+(aq)+NO3–(aq)+Ca2++2Cl–(aq)2AgCl(s)+Ca+2(aq)+2NO3–(aq)
44. How many grams of silver chloride can be prepared by the reaction of 100.0ml of 0.20M silver nitrate with 100.0ml of 0.15M calcium chloride.
How much leftover of each ion?
Complete Ionic Equation:
2Ag+(aq)+NO3–(aq)+Ca2++2Cl–(aq)2AgCl(s)+Ca+2(aq)+2NO3–(aq)
0.20M M M M g
0.1000L L L L
ions: Ag NO Ca Cl-
start: mol 0.02mol mol mol
end: mol mol mol ?mol
All the silver ions get used up. Ag+: 0M
No NO3- are used, only spectator ions: NO3-: 0.02mol/.200L = 0.1M
No Ca2+ are used, only spectator ions: Ca2+:0.015mol/.20L=0.075M
But what about the chloride ions?

62. Ag+(aq) + Cl–(aq)  AgCl(s)
44. How many grams of silver chloride can be prepared by the reaction of 100.0ml of 0.20M silver nitrate with 100.0ml of 0.15M calcium chloride.
How much leftover of each ion?
Net Ionic Equation:
Ag+(aq) + Cl–(aq)  AgCl(s)
ions: Ag NO Ca Cl-
start: mol 0.02mol mol mol
end: mol mol mol mol
All the silver ions get used up. Ag+: 0M
No NO3- are used, only spectator ions: NO3-: 0.02mol/.200L = 0.1M
No Ca2+ are used, only spectator ions: Ca2+:0.015mol/.20L=0.075M
But what about the chloride ions?
They were consumed at a rate of one-to-one with Ag+.
So if 0.02mol Ag+ is consumed, same with Cl-.
That leaves 0.01 moles leftover.
Cl–: 0.010mol/.20L=0.050M

63. Ch4.5 – Acid-Base Reactions
Bronsted-Lowry Theory of acids and bases:
Acid – proton donor
Base – proton acceptor
HCl(aq) + NaOH(aq) 
HC2H3O2(aq) + KOH(aq) 

64. Ex1) What volume of a 0.100M HCl solution is needed to neutralize
25.0mL of 0.350M NaOH?
HCl(aq) + NaOH(aq) 

65. Ex2) In a certain experiment, 28.0ml of 0.250M HNO3
and 53.0ml of 0.320M KOH are mixed.
Calculate the amount of water formed and the amount
of excess H+ or OH-.

66. Acid-Base Titrations
- delivery of a measured volume of soln (usually from a buret)
of know concentration into a soln being analyzed (the analyte).
The point where enough titrant has been added to react
exactly is called the equivalence point,
often indicated by an indicator (substance that changes color.)
This point is often called the endpoint.
Ex3) Benzoic acid, HC7H5O2, is a component of waste effluent released
in some industrial processes. If ml of M NaOH
is required to neutralize it, what volume of benzoic acid was present?
(next slide)

67. Ex3) Benzoic acid, HC7H5O2, is a component of waste effluent released
in some industrial processes. If ml of M NaOH
is required to neutralize it, what volume of benzoic acid was present?
H+ + C7H5O2- + Na+ + OH- 
Ch4 HW#5 p182 45(a,b),47(a,b),49(a,b)

68. a. HClO4(aq) + Mg(OH)2(s) →
Ch4 HW#6 p182 45(a,b),47(a,b),49(a,b)
45. Write the balanced molecular, complete ionic, and net ionic equations for each of the following acid-base reactions.
a. HClO4(aq) + Mg(OH)2(s) →
2H+(aq) +2ClO4-(aq)+Mg+2(aq) + 2(OH)-(aq)→
b. HCN(aq) + NaOH(aq) →
H+(aq) +CN-(aq)+Na+(aq) + (OH)-(aq)→

69. a. HClO4(aq) + Mg(OH)2(s) →
45. Write the balanced molecular, complete ionic, and net ionic equations for each of the following acid-base reactions.
a. HClO4(aq) + Mg(OH)2(s) →
2H+(aq) +2ClO4-(aq)+Mg+2(aq) + 2(OH)-(aq)→H(OH)(l) +Mg+2(aq)+ ClO4-(aq)
H+(aq) + (OH)-(aq)→H(OH)(l)
b. HCN(aq) + NaOH(aq) →
H+(aq) +CN-(aq)+Na+(aq) + (OH)-(aq)→

70. a. HClO4(aq) + Mg(OH)2(s) →
45. Write the balanced molecular, complete ionic, and net ionic equations for each of the following acid-base reactions.
a. HClO4(aq) + Mg(OH)2(s) →
2H+(aq) +2ClO4-(aq)+Mg+2(aq) + 2(OH)-(aq)→H(OH)(l) +Mg+2(aq)+ ClO4-(aq)
H+(aq) + (OH)-(aq)→H(OH)(l)
b. HCN(aq) + NaOH(aq) →
H+(aq) +CN-(aq)+Na+(aq) + (OH)-(aq)→H(OH)(l) +Na+(aq)+ CN-(aq)

71. 47. Write the balanced molecular, complete ionic, and net ionic equations for the reactions that occur when the following are mixed.
a. potassium hydroxide (aqueous) and nitric acid
KOH(aq) + HNO3(aq) 
b. barium hydroxide (aqueous) and hydrochloric acid
Ba(OH)2(aq) + HCl(aq) 

72. K+(aq)+OH-(aq)+H+(aq)+NO3-(aq)H+(aq)+OH-(aq)+K+(aq)+NO3-(aq)
47. Write the balanced molecular, complete ionic, and net ionic equations for the reactions that occur when the following are mixed.
a. potassium hydroxide (aqueous) and nitric acid
K+(aq)+OH-(aq)+H+(aq)+NO3-(aq)H+(aq)+OH-(aq)+K+(aq)+NO3-(aq)
H+(aq)+ OH-(aq)  H(OH)(l)
b. barium hydroxide (aqueous) and hydrochloric acid
Ba2+(aq)+2(OH)-(aq)+2H+(aq)+2Cl-(aq) 2H+(aq)+2(OH)-(aq)+ Ba2+(aq)+ 2Cl-

73. HCl(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ Cl-(aq)
49. What volume of each of the following acids will react completely
with mL of M NaOH?
a M HCl
HCl(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ Cl-(aq)
0.100M M
?L L
b M HNO3

74. HCl(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ Cl-(aq)
49. What volume of each of the following acids will react completely
with mL of M NaOH?
a M HCl
HCl(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ Cl-(aq)
0.100M M
?L L
b M HNO3
HNO3(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ NO3-(aq)
0.150M M

75. HCl(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ Cl-(aq)
49. What volume of each of the following acids will react completely
with mL of M NaOH?
a M HCl
HCl(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ Cl-(aq)
0.100M M
?L L
b M HNO3
HNO3(aq) + NaOH(aq)→H(OH)(l) +Na+(aq)+ NO3-(aq)
0.150M M

76. The following data was obtained from a regular chemistry lab group
Lab 4.2 Pre-lab Questions
The following data was obtained from a regular chemistry lab group
conducting this lab:
Trial 1
NaOH
Initial Volume
Final Volume
Volume Used
Molarity
0.100M
1mL
12mL
11mL
HCl
0.0157M
0.016M
0.02M
2mL
9mL
7mL

77. but it definitely lacked precision.
Trial 1
NaOH
Initial Volume
Final Volume
Volume Used
Molarity
0.100M
1mL
12mL
11mL
HCl
0.0157M
0.016M
0.02M
2mL
9mL
7mL
3. Knowing my regular chem classes, this trial may have lacked accuracy,
but it definitely lacked precision.
Please list the obvious non-precise measurements.
4. Look at your calculator answer. Round the answer to the correct number
of significant digits. If you look at the first 3 digits on your calculator
screen, how different do your 2 answers look?

78. 5. If the actual molarity of HCl was 0.150M, please find the % error
Trial 1
NaOH
Initial Volume
Final Volume
Volume Used
Molarity
0.100M
1mL
12mL
11mL
HCl
0.0157M
0.016M
0.02M
2mL
9mL
7mL
5. If the actual molarity of HCl was 0.150M, please find the % error
for the answer with the correct sig digs.
6. Can you see how precise measuring can be as important
as accurate measuring?

79. Ch4 HW#7 Mid Chapter Review p180+ 16c,18c,24b,54
Lab4.2 Neutralization
Volume of NaOH: ____ (measured)
Molarity of NaOH: 0.200
Volume of HCl: ____ (measured)
Molarity of HCl: ?

80. Ch4 HW#7 Mid Chapter Review p180+ 16c,18c,24b,54
16c. A g sample of iron is dissolved in a small amount of concentrated nitric acid forming Fe3+ ions in solution and is diluted
to a total volume of 500.0ml. Calculate the molarity of Fe3+.

81. 16c. A g sample of iron is dissolved in a small amount of concentrated nitric acid forming Fe3+ ions in solution and is diluted
to a total volume of 500.0ml. Calculate the molarity of Fe3+.
Fe(s) + HNO3(aq)  Fe3+ (aq) + NO3-(aq) + H2(g)

82. 18c.Calculate the concentration of all ions present in 5.00g of NH4Cl
in 500.0mL of solution.
NH4Cl H2O NH4+ + Cl-

83. 18c.Calculate the concentration of all ions present in 5.00g of NH4Cl
in 500.0mL of solution.
NH4Cl H2O NH4+ + Cl-

84. 24b. How would you prepare 1.00 L of a 0.50M HCl soln from
“concentrated” (12M) reagent?

85. 24b. How would you prepare 1.00 L of a 0.50M HCl soln from
“concentrated” (12M) reagent?

86. 2HNO3(aq) + Ca(OH)2(aq)→ 2H(OH)(l) +Na2+(aq)+ NO3-(aq)
54. What volume of M calcium hydroxide is required to neutralize
35.00 mL of M nitric acid?
2HNO3(aq) + Ca(OH)2(aq)→ 2H(OH)(l) +Na2+(aq)+ NO3-(aq)
0.050M M
L ?L

87. 2HNO3(aq) + Ca(OH)2(aq)→ 2H(OH)(l) +Na2+(aq)+ NO3-(aq)
54. What volume of M calcium hydroxide is required to neutralize
35.00 mL of M nitric acid?
2HNO3(aq) + Ca(OH)2(aq)→ 2H(OH)(l) +Na2+(aq)+ NO3-(aq)
0.050M M
L ?L

88. Ch4.6 Oxidation-Reduction Reactions (Redox)
Redox reactions involve the transfer of electrons.
Ex1) Na(s) + Cl2(g) 

89. In redox reactions, one element is oxidized (loses electrons),
one element is reduced (gains electrons).
OIL RIG
(Oxidation Is Losing, Reducing Is Gaining)
(reduced in charge)
Oxidation numbers – in covalent bonds, where electrons are shared,
they are rarely shared equally. So we assign a charge to each.
Here’s the rules:

90. Oxidation numbers – in covalent bonds, where electrons are shared,
they are rarely shared equally. So we assign a charge to each.
Here’s the rules:
1. Free elements are 0. Exs: Na(s), O2(g)
2. Monatomic ions take ox #’s
based on their column: Exs: Na: +1, Cl: -1
3. Fluorine is always -1.
4. Oxygen is usually Exs: CO, CO2, SO2, SO3
Exceptions: the O22- group is -1, like in H2O2
when bonded to fluorine it +2, OF2.
5. With nonmetals, H is +1 Exs: HCl, NH3, H2O, CH4
6. Sum in a compound adds up to 0, or
adds up to the sum of the whole polyatomic ion charge.
Exs: NH4+

91. c) NO3- d) Fe2O3 Ex2) Assign oxidation states to all the atoms:
a) CO2 b) SF6
c) NO3- d) Fe2O3

92. Ex3) In the following reaction, identify which element is oxidized
and which is reduced:
2Al(s) I2(s)  2AlI3(s)
Al: oxidized
I2: reduced
I2 is referred to as the oxidizing agent (takes electrons).
Al is the reducing agent (furnishes electrons).

93. Ex4) In the following reaction, identify which element is oxidized
and which is reduced:
2PbS(s) O2(g)  2PbO(s) SO2(g)
Ch4 HW#8 p ,59,61(a,b)

94. c. K4Fe(CN)6 (Fe only) d. (NH4)2HPO4
Ch4 HW#8 p ,59,61(a,b)
57. Assign oxidation states for all atoms in each of the following compounds.
a. KMnO4 b. NiO2
c. K4Fe(CN)6 (Fe only) d. (NH4)2HPO4
e. P4O6 f. Fe3O4
g. XeOF4 h. SF4
i. CO j. Na2C2O4

95. c. K4Fe(CN)6 (Fe only) d. (NH4)2HPO4
57. Assign oxidation states for all atoms in each of the following compounds.
a. KMnO4 b. NiO2
(+1)___(-8) ___(-4)
c. K4Fe(CN)6 (Fe only) d. (NH4)2HPO4
(+4)___(-6) (+2)(+1)___(-8)
e. P4O6 f. Fe3O4
___(-12) ___(-8)
g. XeOF4 h. SF4
___(-2)(-4) ___(-4)
i. CO j. Na2C2O4
___(-2) (+2)___(-8)

96. c. K4Fe(CN)6 (Fe only) d. (NH4)2HPO4
57. Assign oxidation states for all atoms in each of the following compounds.
a. KMnO4 b. NiO2
(+1)+7(-8) (-4)
c. K4Fe(CN)6 (Fe only) d. (NH4)2HPO4
(+4)+2(-6) (+2)(+1)+5(-8)
e. P4O6 f. Fe3O4
+3each(-12) +8/3each(-8)
g. XeOF4 h. SF4
+6(-2)(-4) (-4)
i. CO j. Na2C2O4
+2(-2) (+2)+6(-8)

97. 59. Assign the oxidation for chlorine in each of the following anion:
OCl-
ClO2-
CLO3-
CLO4-

98. [(-2)___](-1) ClO2- [___ (-4)](-1) ClO3- [___(-6)](-1) ClO4-
59. Assign the oxidation for chlorine in each of the following anion:
OCl-
[(-2)___](-1)
ClO2-
[___ (-4)](-1)
ClO3-
[___(-6)](-1)
ClO4-
[___(-8)](-1)

99. [(-2)+1](-1) ClO2- [+3 (-4)](-1) ClO3- [+5(-6)](-1) ClO4- [+7(-8)](-1)
59. Assign the oxidation for chlorine in each of the following anion:
OCl-
[(-2)+1](-1)
ClO2-
[+3 (-4)](-1)
ClO3-
[+5(-6)](-1)
ClO4-
[+7(-8)](-1)

100. b. Zn(s) + 2HCI(aq) ZnCI2(aq) + H2(g)
61(a,b). Specify which of the following are oxidation-reduction reactions, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced.
a. CH4(g) + 2O2(g) CO2(g) + 2H2O(g)
b. Zn(s) + 2HCI(aq) ZnCI2(aq) + H2(g)

101. [+4(-4) ] (0) [+4(-4)] [+2(-2)] -1each -2each +1each
61(a,b). Specify which of the following are oxidation-reduction reactions, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced.
a. CH4(g) + 2O2(g) CO2(g) + 2H2O(g)
[+4(-4) ] (0) [+4(-4)] [+2(-2)]
-1each each +1each
OIL: H lost 2e- so is oxidized, making it the reducing agent.
RIG: O gained 2e- so is reduced, making it the ox agent.
b. Zn(s) + 2HCI(aq) ZnCI2(aq) + H2(g)
(0) [+1(-1)] [+2(-1each)] (0)

102. [+4(-4) ] (0) [+4(-4)] [+2(-2)] -1each -2each +1each
61(a,b). Specify which of the following are oxidation-reduction reactions, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced.
a. CH4(g) + 2O2(g) CO2(g) + 2H2O(g)
[+4(-4) ] (0) [+4(-4)] [+2(-2)]
-1each each +1each
OIL: H lost 2e- so is oxidized, making it the reducing agent.
RIG: O gained 2e- so is reduced, making it the ox agent.
b. Zn(s) + 2HCI(aq) ZnCI2(aq) + H2(g)
(0) [+1(-1)] [+2(-1each)] (0)
OIL: Zn lost 2e- so is oxidized, making it the reducing agent.
RIG: H gained 1e- each so is reduced, making it the ox agent.

103. Ch4.7 - Balancing Redox Equations
Half reactions: break up a redox reaction into 2 parts,
one involving oxidation, one involving reduction.
Slightly different methods if the solution is acidic or basic,
so determine that first.
Ex1) Potassium dichromate, K2Cr2O7, reacts with ethyl alcohol, C2H5OH,
in the following reaction:
H+(aq) + Cr2O72-(aq) + C2H5OH  Cr+3(aq) + CO2(aq) + H2O(l)
(yellow) (violet)

104. Ex1) Potassium dichromate, K2Cr2O7, reacts with ethyl alcohol, C2H5OH,
in the following reaction: (Acidic)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(yellow) (violet)
Step1: Write ½ rxns.
Step2: a. b. c. d.
Step3:
Step4:
Step5:
Reduction ½ rxn:
Oxidation ½ rxn:

105. H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.)
a. Balance all except H n O. b. c. d.
Step3:
Step4:
Step5:
Reduction ½ rxn: Cr2O72-(aq)  Cr+3(aq)
Oxidation ½ rxn: C2H5OH(l)  CO2(aq)

106. H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.)
a. Balance all except H n O.
b. Balance O using H2O. c. d.
Step3:
Step4:
Step5:
Reduction ½ rxn: Cr2O72-(aq)  2Cr+3(aq)
Oxidation ½ rxn: C2H5OH(l)  CO2(aq)

107. H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.)
a. Balance all except H n O.
b. Balance O using H2O.
c. Balance H using H+. d.
Step3:
Step4:
Step5:
Reduction ½ rxn: Cr2O72-(aq)  2Cr+3(aq) + 7H2O(l)
Oxidation ½ rxn: C2H5OH(l)  CO2(aq)

108. H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.)
a. Balance all except H n O.
b. Balance O using H2O.
c. Balance H using H+.
d. Balance charge using electrons.
Step3:
Step4:
Step5:
Reduction ½ rxn: H+(aq) + Cr2O72-(aq)  2Cr+3(aq) + 7H2O(l)
Oxidation ½ rxn: C2H5OH(l)  CO2(aq)

109. H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.) (Repeat w 2nd.)
a. Balance all except H n O.
b. Balance O using H2O.
c. Balance H using H+.
d. Balance charge using electrons.
Step3:
Step4:
Step5:
Reduction ½ rxn: 6e- + 14H+(aq) + Cr2O72-(aq)  2Cr+3(aq) + 7H2O(l)
Oxidation ½ rxn: C2H5OH(l)  CO2(aq)

110. H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.) (Repeat w 2nd.)
a. Balance all except H n O.
b. Balance O using H2O.
c. Balance H using H+.
d. Balance charge using electrons.
Step3: Equalize electrons
Step4:
Step5:
Reduction ½ rxn: 6e- + 14H+(aq) + Cr2O72-(aq)  2Cr+3(aq) + 7H2O(l)
Oxidation ½ rxn: C2H5OH(l) + 3H2O(l)  2CO2(aq) + 12H+(aq)+12e-

111. H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.) (Repeat w 2nd.)
a. Balance all except H n O.
b. Balance O using H2O.
c. Balance H using H+.
d. Balance charge using electrons.
Step3: Equalize electrons
Step4: Add the ½ reactions together
Step5:
Reduction ½ rxn:2(6e- +14H+(aq) +Cr2O72-(aq)  2Cr+3(aq) + 7H2O(l))
Oxidation ½ rxn: C2H5OH(l) + 3H2O(l)  2CO2(aq) + 12H+(aq)+12e-

112. C2H5OH(l)+16H+(aq)+2Cr2O72-(aq) 2CO2(aq)+4Cr+3(aq)+11H2O(l)
(+6)
(–2)
(+3)
(+4)
H+(aq) + Cr2O72-(aq) + C2H5OH(l)  Cr+3(aq) + CO2(aq) + H2O(l)
Step1: Write ½ rxns.
Step2: Balance ½ rxns. (Start with 1st.) (Repeat w 2nd.)
a. Balance all except H n O.
b. Balance O using H2O.
c. Balance H using H+.
d. Balance charge using electrons.
Step3: Equalize electrons.
Step4: Add the ½ rxns and cancel identical items.
Step5: Check that elements and charges balance.
Reduction ½ rxn:12e- +28H+(aq)+2Cr2O72-(aq)  4Cr+3(aq) +14H2O(l)
Oxidation ½ rxn: C2H5OH(l) + 3H2O(l)  2CO2(aq) + 12H+(aq)+12e-
C2H5OH(l)+16H+(aq)+2Cr2O72-(aq) 2CO2(aq)+4Cr+3(aq)+11H2O(l)

113. Ex2) An aqueous soln of cyanide ion is often used to extract silver
from ore. It occurs in a basic soln in the following reaction:
Ag(s) + CN-(aq) + O2(g)  Ag(CN)2-(aq)
Balance using ½ rxn method.

114. HW#63b) Balance using ½ rxn method:
I-(aq) + ClO-(aq)  I3-(aq) + Cl-(aq)
Ch4 HW#9 p183 63(a,b), 65(a,b)

115. Ch4 HW#9 p183 63(a,b), 65(a,b)
63. Balance the following oxidation-reduction reactions that occur in acidic solutions.
a. Zn(s) + HCl(aq) Zn2+(aq) + H2(g)

116. 63. Balance the following oxidation-reduction reactions that occur in acidic solutions.
b. I-(aq) + ClO-(aq) I3-(aq) + Cl-(aq)

117. 65. Balance the following oxidation-reductions reactions that occur in basic solutions.
a. Al(s) + MnO4-(aq) MnO2(s) + Al(OH)4-(aq)

118. 65. Balance the following oxidation-reductions reactions that occur in basic solutions.
b. Cl2(g) Cl-(aq) + OCl-(aq)

119. Ch4 HW#10 p (a,b),66(a,b)
64. Balance the following oxidation-reduction reactions that occur in acid solution using the half-reactions method.
a. Cu(s) + NO3-(aq) Cu2+(aq) + NO(aq)

120. 64. Balance the following oxidation-reduction reactions that occur in acid solution using the half-reactions method.
b. Cr2O72-(aq) + Cl-(aq) Cr3+(aq) + Cl2(g)

121. 66. Balance the following oxidation-reduction reactions the occur in basic solution.
a. Cr(s) + CrO42(aq) Cr(OH)3(s)

122. 66. Balance the following oxidation-reduction reactions the occur in basic solution.
b. MnO4-(aq) + S2-(aq) MnS(s) + S(s)

123. Ch4 Rev#1 p c,16b,18d, 22,24e, 36(a,b)
12c. Show how Ca(OH)2 “breaks up” into its component ions
dissolving in water.

124. 16b. An 853.5-mg sample of KIO3 is dissolving in enough water
to make mL of solution. Calculate the molarity.

125. 18d. Calculate the concentration of all ions present of 1.00 g K3PO4
in mL of solution.

126. 22. How many grams of NaOH are contained in 250.0 mL
of a M sodium hydroxide solution.

127. 24e. How would you prepare 1.00 L of a 0.50 solution
of sodium carbonate from the pure solid.

128. 36. Write net ionic equations for the reaction, if any, when aqueous
36. Write net ionic equations for the reaction, if any, when aqueous solutions of the following are mixed.
a) Cobalt(III) chloride and sodium hydroxide.
b)Silver nitrate and ammonium carbonate.
Ch4 Rev#2 p , 53, 62a, 67

129. 42. What mass of barium sulfate is produced when 100.0 mL
Ch4 Rev#2 p , 53, 62a, 67
42. What mass of barium sulfate is produced when mL
of a 0.100M solution of barium chloride is mixed with mL
of a 0.100M solution of iron(III) sulfate?
Before After Ba Fe Cl
SO4 Cl
SO4
SO4

130. 53. A 25.00 mL sample of hydrochloric acid solution requires 24.16 mL
of M sodium hydroxide for complete neutralization.
What is the concentration of the original hydrochloric acid solution?

131. 62a. Specify if Cu(s) + 2Ag+(aq)  2Ag(s) +Cu2+(aq) is a oxidation-reduction reaction, and identify the oxidizing agent, the reducing agent, the substance being oxidized, and the substance being reduced.

132. NaCl(aq) + H2SO4(aq) + MnO2(s) 
67. Chlorine gas was first prepared in 1774 by C.W. Scheele by oxidizing sodium chlorine with manganese(IV) oxide. The reaction is:
NaCl(aq) + H2SO4(aq) + MnO2(s) 
Na2SO4(aq) + MnCl2(aq) + H2O(l) + Cl2(g)