1. Unit B Chapter 4 Electrolytes
Precipitation (aka Double Replacement or Metathesis) Reactions
Acids & Bases
Neutralization Reactions
Oxidation Reduction
Concentration of Solutions
Solution Stoichiometry

2. Reactions in Aqueous Solutions
Unit B Chapter , 4.5
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3. Which of the compounds listed below are insoluble (select all that apply):
NiCO3
Ba(NO3)2
C6H12O6
Na3PO3
ZnS
K2CrO4
Al2(SO4)3
SnF2
Do the problem without your solubility table.

4. Which of the compounds listed below are insoluble:
NiCO3
Ba(NO3)2
C6H12O6
Na3PO3
ZnS
K2CrO4
Al2(SO4)3
SnF2
Remember that nitrates and alkali salts are always soluble.
Sugar is also of course soluble.
Sulfates are usually soluble
Carbonates and sulfides are usually NOT soluble
Do the problem without your solubility table.

5. In the following reaction, which ions are spectator ions: AgNO3 + NaCl → NaNO3 + AgCl ?
Ag+ and NO3−
Na+ and Cl−
Cl− and NO3−
Na+ and NO3−
Ag+ and Cl−
Can you do the problem without your solubility table?

6. In the following reaction, which ions are spectator ions: AgNO3 + NaCl → NaNO3 + AgCl ?
Ag+ and NO3−
Na+ and Cl−
Cl− and NO3−
Na+ and NO3−
Since silver chloride is the precipitate, the nitrate and alkali salts are the spectator ions.
Ag+ and Cl−
Can you do the problem without your solubility table?

7. Identify the precipitate when sodium hydroxide is combined with aluminum nitrate.
NaNO3
AlOH3
NaOH
AlOH
Al(OH)3
Do the problem without your solubility table.

8. Alkali nitrates will always be soluble.
Identify the precipitate when sodium hydroxide is combined with aluminum nitrate.
NaNO3
AlOH3
NaOH
AlOH
Al(OH)3
Alkali nitrates will always be soluble.
By process of elimination, the precipitate must be the aluminum hydroxide.
Do the problem without your solubility table.

9. 133 g of aluminum chloride in 1 L of water would be considered (select all that apply)
soluble
ionized
dissociated
aqueous
concentrated
dilute
weak electrolyte
strong electrolyte
acidic

10. 133 g of AlCl3 in 1 L of water would be considered
AlCl3 → Al Cl−
soluble
ionized
dissociated
aqueous
concentrated
dilute
weak electrolyte
strong electrolyte
acidic
generally <0.1 M is considered dilute
(for reasons you don’t know yet…)
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11. Electrolytes Compounds that dissolve and dissociate into ions
Strong or weak = amount ionized
Concentrated or dilute = amount dissolved
Electrolytes are
Soluble ionic compounds
Acids or bases
Molecular compounds tend to be non-electrolytes

12. Dissolving & Dissociating
When ionic compounds dissolve they dissociate
Observe the orientation of the water molecules as the solvate around the dissociated ions
When molecular compounds dissolve, they do not dissociate
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13. Which solution represented below is a nonelectrolyte?1 2 3

14. Which solution represented below is a nonelectrolyte?1 2 3 1
there are no ions in the solution
Which representation would coduct electricity the best?

15. Write the reaction that best represents the dissolving of magnesium chloride in water
MgCl → Mg(aq) + Cl(aq)
MgCl → Mg+ + Cl−
MgCl2 → Mg (Cl−)2
MgCl2 → Mg Cl−2
MgCl2 → Mg + Cl2
MgCl2 → Mg Cl−

16. Write the reaction that best represents the dissolving of magnesium chloride in water
MgCl → Mg(aq) + Cl(aq)
MgCl → Mg+ + Cl−
MgCl2 → Mg (Cl−)2
MgCl2 → Mg Cl−2
MgCl2 → Mg + Cl2
MgCl2 → Mg Cl−
Be sure you know the correct charges, and show the charge on the dissociated ions.
Remember that multiple amounts of the same ion separate from each other, 2Cl− not Cl2−

17. Write the reaction that best represents the dissolving of perchloric acid in water
HClO4 → H+ + ClO4−
HClO4 → H ClO−
HClO4 → H+ + Cl− + 4O2−

18. Write the reaction that best represents the dissolving of perchloric acid in water
HClO4 → H+ + ClO4−
HClO4 → H ClO−
HClO4 → H+ + Cl− + 4O2−

19. Write the reaction that best represents the dissolving of chlorous acid in water
HClO2 → H+ + ClO2−
HClO2 → H ClO−
HClO2 → H+ + Cl− + 2O2−
HClO2  H+ + ClO2−
HClO2  H ClO−

20. Write the reaction that best represents the dissolving of chlorous acid in water
HClO2 → H+ + ClO2−
HClO2 → H ClO−
HClO2 → H+ + Cl− + 2O2−
Polyatomic ions do NOT break up in aqueous solutions, so the chlorite ion does not break apart in solution.
HClO2  H+ + ClO2−
This is a weak acid so you should use the double arrows to indicate only some of the acid ionizes.
HClO2  H ClO−

21. Rank the following in order of increasing conductivity in water: (equal moles of each substance put in the water) C6H12O6, KBr, HF, Zn(OH)2
Least conductive → more conductive
C6H12O6 < KBr < HF < Zn(OH)2
Zn(OH)2 < C6H12O6 < HF < KBr
C6H12O6 < Zn(OH)2 < HF < KBr
C6H12O6 < HF < Zn(OH)2 < KBr
C6H12O6 < Zn(OH)2 < KBr < HF
KBr < Zn(OH)2 < HF < C6H12O6

22. Rank the following in order of increasing conductivity in water: (equal moles of each substance put in the water) C6H12O6, KBr, HF, Zn(OH)2
Remember that conductivity is related to the amount of ions in solution
C6H12O6 < KBr < HF < Zn(OH)2
Zn(OH)2 < C6H12O6 < HF < KBr
C6H12O6 < Zn(OH)2 < HF < KBr
Molecular sugar is least conductive, next is zinc hydroxide, because although it is a base (and actually a strong base), it is very insoluble, hydrofluoric acid is weak, and KBr is a soluble salt.
Time to memorize the 7 strong acids: HCl, HBr, HI, HNO3, H2SO4, HClO3, HClO4
C6H12O6 < Zn(OH)2 < KBr < HF
KBr < Zn(OH)2 < HF < C6H12O6

23. C3H7OH < HClO < KCl < AlCl3
Rank the following in order of increasing conductivity in water: (equal moles of each substance put in the water) C3H7OH, KCl, HClO, AlCl3
C3H7OH < HClO < KCl < AlCl3
AlCl3 < C3H7OH < KCl <HClO
HClO < C3H7OH < KCl < AlCl3
C3H7OH < HClO < KCl = AlCl3
C3H7OH < KCl < AlCl3 < HClO

24. Rank the following in order of increasing conductivity in water: (equal moles of each substance put in the water) C3H7OH, KCl, HClO, AlCl3
C3H7OH < HClO < KCl < AlCl3
C3H7OH is an alcohol, it is molecular and therefore least conductive.
HClO, perchlorous acid is a weak acid.
KCl, AlCl3 are salts and you might think are equally conductive, but because AlCl3 dissociates into 4 ions (Al+3 and 3 Cl−) it produces more ions per equal concentration and thus is a more conductive solution.
AlCl3 < C3H7OH < KCl <HClO
HClO < C3H7OH < KCl < AlCl3
C3H7OH < HClO < KCl = AlCl3
C3H7OH < KCl < AlCl3 < HClO

25. Calculate the concentration of chloride ion when 5
Calculate the concentration of chloride ion when 5.8 g of sodium chloride and 4.8 g of magnesium chloride is dissolved to produce 400 ml of solution.
No Calculator
0.05 M
0.50 M
0.10 M
2.0 M
0.15 M
0.40 M
0.20 M
0.75 M

26. Calculate the concentration of chloride ion when 5
Calculate the concentration of chloride ion when 5.8 g of sodium chloride and 4.8 g of magnesium chloride is dissolved to produce 400 ml of solution.
0.05 M
0.10 M
0.15 M
0.20 M
0.50 M
2.0 M
No Calculator

27. When 30. ml of 0. 50 M K2SO4 are added to 70. mL of 0
When 30. ml of 0.50 M K2SO4 are added to 70. mL of 0.50 M of KMnO4, the resulting concentration of potassium is
No Calculator
1.0
0.85
0.65
0.50
0.33 27

28. When 30. ml of 0. 50 M K2SO4 are added to 70. mL of 0
When 30. ml of 0.50 M K2SO4 are added to 70. mL of 0.50 M of KMnO4, the resulting concentration of potassium is
1.0
0.85
0.65
0.50
0.33
No Calculator