Chemistry 12
Unit 3 Solubility Equilibrium
Unit 3 Pre-Test Solubility Equilibrium
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1. Which of the following solutes is a non–electrolyte?
A. H2CO3
B. H2C2O4
C. CH3OCH3
D. CH3COOH
2. Which best describes the equilibrium in a saturated solution?
A. The rate of crystallization determines the solubility.
B. The rate of crystallization equals the rate of dissolving.
C. There is no solid solute on the bottom of the container.
D. The solute is completely dissolved and the equilibrium favours the products.
3. What is a characteristic of a saturated solution of PbBr2 ?
A. [Pb2+] = [Br–]2
B. All the PbBr2(s) must be dissolved.
C. The system temperature must be 25°C.
D. The rate of crystallization equals the rate of dissolving.
4. What are the ion concentrations that result when 1.0 × 10–2 mol BeF2 is dissolved to produce
1.00 × 102 L of solution?
[Be2+]
[F–]
–4
A.
1.0 × 10 M
1.0 × 10–4 M
B.
1.0 × 10–4 M
2.0 × 10–4 M
–2
C.
1.0 × 10 M
1.0 × 10–2 M
–2
D.
1.0 × 10 M
2.0 × 10–2 M
5. Which of the following is an appropriate unit for solubility?
A. mol/L
B. L/mol
C. kJ/mol
D. s/L
6. Which compound will have the greatest solubility?
A. CoS
B. CuS
C. FeS
D. MgS
ver. 04/14/2012
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Chemistry 12
Unit 3 Solubility Equilibrium
7. What is observed when equal volumes of 0.2 M CuNO3 and 0.2 M AlCl3 are mixed?
A. CuCl precipitates.
B. Al(NO3)3 precipitates.
C. Both CuCl and Al(NO3)3 precipitate.
D. No precipitate is formed.
8. Which of the following will form a saturated solution?
A. 0.10 mol BaS added to 2.0 L of water
B. 0.10 mol PbSO3 added to 1.0 L of water
C. 0.20 mol H2SO3 added to 2.0 L of water
D. 0.20 mol Pb(NO3)2 added to 2.0 L of water
9. Which compound will have a solubility greater than 0.1 M at 25°C ?
A. SrS
B. CoS
C. BaSO4
D. Ag2SO4
10. What happens when equal volumes of 0.20 M Sr(OH)2 and 0.20 M Fe2(SO4)3 are mixed?
A. No precipitate is formed.
B. Only SrSO4 precipitates.
C. Only Fe(OH)3 precipitates.
D. Both SrSO4 and Fe(OH)3 precipitate.
11. What is the net ionic equation for the reaction between equal volumes of 0.20 M SrS and 0.20 M
BeSO4?
A. Be2+(aq) + S2–(aq)  BeS(s)
B. Sr2+(aq) + SO42–(aq)  SrSO4(s)
C. SrS(aq) + BeSO(aq)  SrSO4(s) + BeS(s)
D. Sr2+(aq) + S2–(aq) + Be2+(aq) + SO42–(aq)  SrSO4(s) + Be2+(aq) + S2–(aq)
12. Which of the following is the complete ionic equation for the precipitation reaction between
Fe(NO3)3(aq) and Na2CO3(aq)?
A. 2Fe3+(aq) + 3CO32–(aq)  Fe2(CO3)3(s)
B. 2Fe(NO3)3(aq) + 3Na2CO3(aq)  Fe2(CO3)3(s) + 6NaNO3(s)
C. Fe3+(aq) + 3NO3–(aq) + 2Na+(aq) + CO32–(aq)  Fe2(CO3)3(s) + Na+(aq) + NO3–(aq)
D. 2Fe3+(aq) + 6NO3–(aq) + 6Na+(aq) + 3CO32–(aq)  Fe2(CO3)3(s) + 6Na+(aq) + 6NO3–(aq)
13. What is the complete ionic equation for the precipitation reaction between MgS(aq) and Sr(OH)2(aq)?
A. Mg2+(aq) + 2OH–(aq)  Mg(OH)2(s)
B. MgS(aq) + Sr(OH)2(aq)  SrS(aq) + Mg(OH)2(s)
C. Mg2+(aq) + S2–(aq) + Sr2+(aq) + 2OH–(aq)  Mg2+(aq) + 2OH–(aq) + SrS(s)
D. Mg2+(aq) + S2–(aq) + Sr2+(aq) + 2OH–(aq)  Sr2+(aq) + S2–(aq) + Mg(OH)2(s)
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Chemistry 12
Unit 3 Solubility Equilibrium
14. Which equation has the Ksp expression: Ksp = [Al3+]2[SO42–]3
A. 2Al3+(aq) + 3SO42–(aq)  Al2(SO4)3(s)
B. Al2(SO4)3(s)  Al3+(aq) + SO42–(aq)

C. Al2(SO4)3(s)  2Al3+(aq) + 3SO42–(aq)

3+
D. 3Al (aq) +SO42–(aq)  Al2(SO4)3(s)

15. Given the solubility equilibrium:
2+
–
Fe(OH)2(s) 
 Fe (aq) + 2OH (aq)
What is the Ksp expression?
A. Ksp = [Fe2+][2OH−]
B. Ksp = [Fe2+][OH−]2
C.
[Fe2+][OH−]2
Ksp = [Fe(OH) ]
2
D.
[Fe(OH)2]
Ksp = [Fe2+][OH−]2
16. What is the Ksp expression for BaSO4 in a solution that also contains Na2SO4 ?
A. Ksp = [Na+]2[SO42−]
B.
[Ba2+][SO42−]
Ksp = [BaSO ]
4
C. Ksp = [Ba2+][SO42−]
D. Ksp = [Ba2+][Na+]2[SO42−]2
17. What is the Ksp expression for the low solubility salt formed when Na2SO3(aq) and FeCl3(aq) are
mixed?
A. Ksp = [Na+][Cl–]
B. Ksp = [Fe3+][Cl–]3
C. Ksp = [Fe3+][SO32–]
D. Ksp = [Fe3+]2[SO32–]3
18. Which of the following will have the lowest solubility?
A. FeS
B. BaSO4
C. FeSO4
D. NaNO3
19. What is the Ksp for the salt Ag2CrO4 when its solubility is found to be 2.9 × 10–4 M?
A. 9.8 × 10–11
B. 2.4 × 10–11
C. 8.4 × 10–8
D. 2.9 × 10–4
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Chemistry 12
Unit 3 Solubility Equilibrium
20. What is the solubility of barium carbonate?
A. 6.8 × 10–18 M
B. 2.6 × 10–9 M
C. 5.2 × 10–9 M
D. 5.1 × 10–5 M
21. The Ksp for a salt AB is 1.0 × 102 . Which of the following is correct?
Solubility (M) Soluble/Low Solubility
A. 1.0 × 101
soluble
B. 1.0 × 101
low solubility
1
C. 5.0 × 10
soluble
D. 1.0 × 10–1
low solubility
22. Which compound has the lowest solubility?
A. ZnS
B. CuS
C. AgCl
D. SrSO4
23. What is the solubility of the salt PbCl2 ?
A. 1.4 × 10–2 M
B. 2.4 × 10–3 M
C. 3.5 × 10–3 M
D. 1.2 × 10–5 M
24. What is observed when 10.0 mL of 1.0 × 10–4 M AgNO3 is mixed with 30.0 mL of 1.0 × 10–3M NaIO3 ?
A. A precipitate forms since Trial Ksp > Ksp .
B. A precipitate forms since Trial Ksp < Ksp .
C. No precipitate forms since Trial Ksp > Ksp .
D. No precipitate forms since Trial Ksp < Ksp .
25. What is the maximum [Ag+] that can exist in a 8.5 × 10–2 M CO32– solution?
A. 1.0 × 10–10 M
B. 2.0 × 10–5 M
C. 1.0 × 10–5 M
D. 8.5 × 10–2 M
26. A solution is found to contain a [Pb2+] of 0.10 M. What is the maximum [SO42–] that can exist in this
solution before a precipitate forms?
A. [SO42–] = 1.8 × 10–9 M
B. [SO42–] = 1.8 × 10–8 M
C. [SO42–] = 1.8 × 10–7 M
D. [SO42–] = 1.3 × 10–4 M
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Chemistry 12
Unit 3 Solubility Equilibrium
27. What is the maximum [OH–] that can exist in a 5.6 × 10–2 M Mg2+ solution?
A. 2.0 × 10–10 M
B. 1.0 × 10–10 M
C. 1.0 × 10–5 M
D. 5.6 × 10–2 M
28. Which of the following substances will have the least effect on the equilibrium in a saturated solution
of PbI2(s)?
A. HI
B. Na2S
C. NaNO3
D. Pb(NO3)2
29. Given the solubility equilibrium:
 Ca2+(aq) + SO32–(aq)
CaSO3(s) 
The addition of which of the following substances will cause the equilibrium to shift right?
A. CaSO3(s)
B. H2SO4(aq)
C. Na2SO3(aq)
D. Ca(NO3)2(aq)
30. Given the solubility equilibrium:
2+
2–
MnS(s) 
 Mn (aq) + S (aq)
Which of the following substances, when added to the equilibrium, will cause the equilibrium to shift
right?
A. MnS(s)
B. HCl(aq)
C. Na2S(aq)
D. Mn(NO3)2(aq)
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Chemistry 12
Unit 3 Solubility Equilibrium
Written Response
Answer the following questions. Show all calculations leading to your answer. Final answers should be rounded to the correct
number of significant figures and include units where appropriate.
31. (4 marks)
Devise a scheme to individually precipitate and remove two of the cations from a solution containing
Ag+ , Ba2+ and Fe3+. As a part of your scheme, provide the compounds added, the net ionic equations
and the method of removal.
32. (4 marks)
In order to determine the Ksp of BaF2 , a student pipetted 50.00 mL of saturated BaF2 solution into an
evaporating dish and evaporated the water. The following data was obtained:
Mass BaF2 residue and evaporating dish
Mass evaporating dish
59.185 g
59.122 g
Calculate the Ksp of BaF2 .
33. (4 marks)
Will a precipitate form when 25 mL of 0.014 M Pb(NO3)2 is added to 1.000 L of 0.0050 M NaI
solution? Show calculations that support your answer.
34. (4 marks)
A 10.0 mL sample of 0.20 M aluminum nitrate is diluted to 0.200 L. Write the dissociation equation
for aluminum nitrate and determine the concentration of the individual ions in the diluted solution.
35. (4 marks)
Consider the following equilibrium:
2+
–
Fe(OH)2(s) 
 Fe (aq) + 2OH (aq)
What happens to the amount of solid Fe(OH)2 when some HCl is added? On the graph below, sketch
the effect of adding HCl at time t1 .
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Chemistry 12
Unit 3 Solubility Equilibrium
SOLUBILITY PRE-TEST ANSWERS MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
C
B
D
B
A
D
7.
8.
9.
10.
11.
12.
A
B
A
D
B
D
Solubility Equilibrium Pre-Test.docx
13.
14.
15.
16.
17.
18.
D
C
B
C
D
A
19.
20.
21.
22.
23.
24.
A
D
A
B
A
D
25.
26.
27.
28.
29.
30.
C
C
C
C
B
B
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