Chapters 7 and 8 Review Sheet
Terms to be Familiar With:
Solvent
Solubility
Non-electrolyte
Solute
Saturated
Molar concentration
Solution
Unsaturated
Molarity
Aqueous Solution
Supersaturated
Standard Solution
Miscible
Electrolyte
Dissociation Equation
Immiscible
Precipitation reactions
Possible Questions:
1. List and describe three factors that affect the rate of dissolving. (7.2A)
2. A) Draw and describe the process of an ionic compound dissolving in water. (7.2B)
B) Draw and describe the process of a covalent compound dissolving in water.
C) Compare ionic and molecular compounds dissolving in water.
D) Explain the term ‘Like Dissolves Like’ and give examples of each.
E) Give examples of what can and cannot dissolve in water.
3. A) Describe three factors that affect solubility. (7.2 D)
B) Be prepared to discuss thermal pollution and pressure examples as they relate to
solubility.
4. Describe two ways to prepare a standard solution.(7.4)
Problems:
1. Molarity Problems
a. What is the molarity of 70-ml of solution containing 0.15 moles of salt?
b. What is the molarity of a 3.0-L solution that contains 212.5 grams of NaNO3?
c. What mass of glucose, C6H12O6, is needed to make 300-ml of a 0.524 M solution?
d. How many grams of solute are in 0.350 L of 0.754 M KCl solution?
e. What is the volume needed to make a 2.5 M solution containing 0.66 moles of solute?
2. Dilution Problems
a. You must prepare 300-ml of a 0.75 M NaBr solution using 5.5 M NaBr stock solution.
What volume of stock solution would you use?
b. How would you prepare 200-ml of a 1.44 M MgSO4 solution using a 6.49 M MgSO4
solution?
c. Using a 12.0 M HCl stock solution, how would you prepare 500-ml of 1.88 M HCl?
3. Writing and interpreting dissociation equations for single solutions.
In each of the following, write the dissociation equation and state the concentration (molarity)
for the dissociated ions.
a. 0.75 M BaF2.
b. 1.45 M Cu(ClO3)2
c. 22.0 grams of MgSO4 dissolved in 300-ml of water.
d. 54.8 grams of Al2O3 dissolved in 250-ml of water.
4. Writing and interpreting dissociation equations for two solutions.
a. What is the concentration (molarity) of fluoride ions in a solution that results by
mixing 120-ml of 0.55 M CaF2 and 200-ml of 1.66 M KF?
b. What is the concentration (molarity) of sulfate ions in a solution that results by mixing
150-ml of 0.44 M Na2SO4 and 250-ml of 1.13 M Al2(SO4)3?
c. Equal volumes of 0.150 M of NaBr and 0.84 M CaBr2 are mixed together. What is the
molarity of the bromide ion concentration?
d. What is the concentration (molarity) of nitride ions in a solution that results by
mixing 67-grams of Na3N in 100-ml of solution and 115-grams of Mg3N2 in 200-ml
of solution?
5. Soluble or Insoluble
Determine the solubility of each of the following:
a. NaCl
b. BaSO4
c. AlPO4
d. K3PO4
6. Precipitation Reactions.
Complete the following double replacement reactions and determine if any of the products are
precipitates. Each of the following reactants are aqueous solutions.
a. Barium chloride and potassium sulfate
b. Sodium carbonate and magnesium sulfate
c. Lead (II) nitrate and sodium sulfide
7. Solubility Problems. You must use the chart below to answer these questions.
b.
c.
d.
e.
f.
At 20oC, a saturated solution of sodium nitrate contains 100 grams of solute in 100 ml of water.
How many grams of sodium nitrate must be added to saturate the solution at 50oC?
At what temperature do saturated solutions of potassium nitrate and sodium nitrate contain
the same weight of solute per 100 mL of water?
How many grams of potassium chlorate must be added to 1 liter of water to produce a
saturated solution at 50oC?
A saturated solution of potassium nitrate is prepared at 60 oC using 100.mL of water. How many
grams of solute will precipitate out of solution if the temperature is suddenly cooled to 30oC?
What is the smallest volume of water, in mL, required to completely dissolve 39 grams of KNO 3
at 10oC?
Are the following solutions saturated, unsaturated or supersaturated (assume that all three
could form supersaturated solutions)
i. 40. g of KCl in 100 mL of water at 80 oC
ii. 120. g of KNO3 in 100 mL of water at 60oC
iii 80. g of NaNO3 in 100 mL of water at 10oC
Solubility Curves of Pure Substances
150
140
KI
130
120
110
NaNO3
100
grams solute per 100 grams H2O
a.
90
KNO3
80
70
NH4Cl
NH3
60
50
KCl
40
NaCl
30
20
KClO3
10
Ce2(SO4)3
0
0
10
20
30
40
50
60
Temperature/Celsuis
70
80
90
100
Answers:
1 a) 2.1 M
b) 0.83 M
c) 28.3 g
2 a) 41 ml
b) 44.4 ml (and description)
d) 19.7 g
e) 0.26 L
c) 78-ml (and description)
3. a) Ba2+ = 0.75 M; F1- = 1.5 M
b) Cu2+ = 1.45 M; ClO31- = 2.90 M
c) Mg2+ and SO42- = 0.609 M
d) Al3+ = 4.30 M; O2- = 6.45 M
4.
a) 1.5 M
b) 2.3 M
c) 0.92 M
d) 10 M
5.
a. soluble
b. soluble
c. insoluble
d. soluble
6.
a. BaCl2 (aq) + K2SO4(aq)  2 KCl(aq) + BaSO4(aq)
b. Na2CO3(aq) + MgSO4(aq)  MgCO3(s) + Na2SO4(aq)
c. Pb(NO3)2(aq) + Na2S(aq)  2 NaNO3(aq) + PbS(s)
7.
a. 14 grams
b. 72 +/- 2 0C
c. 210 grams
d. 55 +/- 2 grams
e. 170 ml
f. (i) unsaturated
(ii) supersaturated
(iii) saturated